Information recording medium and playback device for playing back 3D images

ABSTRACT

To aim to increase the use efficiency of a screen on which a subtitle is displayed together with a stereoscopic image. A video shift mode is set for each subtitle. When a stereoscopic image is played back, in accordance with the video shift mode of the subtitle, a video plane is shifted upward or downward to perform cropping processing of collecting black frames provided in the upper end and the lower end of the screen in either one of the upper end and the lower end so as to save a display region of the subtitle.

This is a continuation of International Application PCT/JP2010/003998,with an international filing date of Jun. 16, 2010.

TECHNICAL FIELD

The present invention relates to a technology of playing back 3D and 2Dimages.

BACKGROUND ART

The 2D images, also called monoscopic images, are represented by pixelson an X-Y plane that is applied to the display screen of the displaydevice. In contrast, the 3D images have a depth in the Z-axis directionin addition to the pixels on the X-Y plane applied to the screen of thedisplay device.

The 3D images are presented to the viewers (users) by simultaneouslyplaying back the left-view and right-view images to be viewedrespectively by the left and right eyes so that a stereoscopic effectcan be produced. The users would see, among the pixels constituting the3D image, pixels having positive Z-axis coordinates in front of thedisplay screen, and pixels having negative Z-axis coordinates behind thedisplay screen.

It is preferable that an optical disc storing a 3D image hascompatibility with a playback device that can play back only 2D images(hereinafter, such a playback device is referred to as “2D playbackdevice”). This is because, otherwise, two types of discs for 3D and 2Dimages need to be produced so that the 2D playback device can play backthe same content as that stored in a disc for 3D image. Such anarrangement will take a higher cost. It is accordingly necessary toprovide an optical disc storing a 3D image that is played back as a 2Dimage by the 2D play back device, and as a 2D or 3D image by a play backdevice supporting both the 3D and 2D images (hereinafter, such aplayback device is referred to as “2D/3D playback device”).

Patent Literature 1 identified below is one example of prior artdocuments describing technologies for ensuring the compatibility inplayback between 2D and 3D images, with respect to optical discs storing3D images.

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Patent No. 3935507

SUMMARY OF INVENTION Technical Problem

By the way, in the case of a movie work or the like, subtitle data isstored in an optical disc subtitle. Generally, when such a movie work isplayed back, subtitles are overlaid with videos for display. Here, iflong scripts or narrations are included in the movie work, most of ascreen is occupied with display regions for subtitle characters. Ifplayback of a video with a high level of jump-out is performed in thestate where most of the screen is occupied with the display regions forsubtitle characters, subtitles overlap stereoscopic display of thevideo. This results in playback of a stereoscopic image that isextremely difficult to view. There is a method of moving the arrangementposition of the subtitle characters an end of the screen such that thesubtitles does not overlap stereoscopic display of the video. However, astereoscopic effect of a video greatly differs depending on a playbackposition in a plurality of playback sections in the time axis of a videostream. Also, subtitle characters often differ in character amountdepending on the type of language. Accordingly, if any one of the endsof the screen is uniformly fixed as a subtitle display region, the useefficiency of the screen is deteriorated. As a result, even if a userspends his money to purchase an expensive widescreen 3D TV, there mightoccur a case where the user cannot enjoy the stereoscopic effect to thefull.

The present invention provides a recording medium capable of avoidingdegradation of a stereoscopic effect due to decrease of the useefficiency of a screen.

Solution to Problem

The present invention provides a recording medium having recordedthereon a video stream constituting a stereoscopic image, playlistinformation, and a plurality of subtitle streams, wherein the playlistinformation includes a stream selection table and a plurality of piecesof additional information, the stream selection table shows a streamnumber, a stream entry, and a stream attribute, with respect to each ofthe subtitle streams to be permitted to be played back in a monoscopicplayback mode, the pieces of additional information each correspond to astream number, and the pieces of additional information each include aregion-saving flag indicating, as a display region of a subtitle in astereoscopic playback mode of a playback device, an upper end or a lowerend in a video plane, the subtitle is obtained by decoding a subtitlestream corresponding to the piece of additional information, when therecording medium is played back by a playback device, if theregion-saving flag indicates the upper end, the playback device shiftsthe video stream in the video plane in a downward direction, and rendersthe shifted video stream, and if the region-saving flag indicates thelower end, the playback device shifts the video stream in the videoplane in an upward direction, and renders the shifted video stream.

Advantageous Effects of Invention

The additional information including a region-saving flag defining adisplay region of a subtitle is included in a stream selection table foreach playback section in correspondence with a stream number. When theplayback section changes, or when a request for changing the stream isreceived, a stream selection procedure is executed. A stream number inaccordance with the language settings of a playback device is set in astream number register. As a result, a region-saving flag indicated by apiece of additional information corresponding to the set stream numberis provided with the playback device. With this structure, it ispossible to realize control in which a display region of a subtitle issaved in the upper end of the screen in a playback section and a displayregion of a subtitle is saved in the lower end of the screen in anotherplayback section.

The cinema scope size (1:2.35) is generally used for the aspect ratio ofvideo of movies. In the case where a video is stored in an optical discsuch as a BD-ROM, a main feature video is disposed in the center of anHD video having the aspect ratio of 16:9 without changing the aspectratio, and a black frame is inserted into each of the upper side and thelower side of the HD video. Accordingly, with the above structure, it ispossible to display subtitles in a large subtitle display regiongenerated by collecting black frames located above and below the mainfeature video to one of the upper end and the lower end of the videoplane. This can improve the use efficiency of the screen, therebyimproving the stereoscopic effect.

(Additional Technical Problem)

According to 3D videos in which the stereoscopic effect is realizedusing the parallax difference between main-view image and a sub-viewimage, the parallax difference differs depending on the screen size ofdisplay device. This causes difference in the depth of images dependingon the screen size. As a result, if a 3D video created for viewing in adisplay device with a large screen is viewed in a display device with asmall screen, the 3D video is not powerful and less width is displayedin such a display device than a creator of the 3D video has expected. Onthe other hand, a 3D video created for viewing in a display device witha small screen is viewed in a display device with a large screen, anexcessive sense is given to the 3D video and this causes a viewer tosuffer from eye strain.

The present invention aims to provide a recording medium that is capableof preventing occurrence of negative influence exerted by viewing of a3D video in a display device with a screen whose size is different fromthat assumed in the creation of the 3D video.

A recording medium that can solve the above problem is a recordingmedium having recorded thereon a main-view video stream, a sub-viewvideo stream, and meta data, wherein the main-view video stream includesmain-view picture data constituting a main-view of a stereoscopic video,the sub-view video stream includes sub-view picture data constituting asub-view of the stereoscopic video, the meta data includes offsetcorrection values each corresponding to screen size information of eachof a plurality of display devices, and the offset correction valuedefines an offset for shifting, in a leftward direction or a rightwarddirection of a horizontal coordinate, at least one of a main-view videoplane in which the main-view picture data is to be rendered and asub-view video plane in which the sub-view picture data is to berendered.

By giving, to picture data, an offset defined in screen size informationfor each display screen size so as to shift the video plane, it ispossible to give an appropriate parallax difference to a stereoscopicimage depending on each screen size. As a result, with the abovestructure, it is possible to prevent occurrence of negative influenceexerted by viewing of a 3D video in a display device with a screen whosesize is different from that assumed in the creation of the 3D video.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A through 1C show a home theater system that is composed of arecording medium being a package medium, a playback device being aplayer device, a display device, and glasses.

FIG. 2 shows the user's head on the left side of the drawing and theimages of a dinosaur skeleton seen respectively by the left eye and theright eye of the user on the right side of the drawing.

FIG. 3 shows one example of the internal structures of the base-view anddependent-view video streams for the stereoscopic viewing.

FIG. 4 shows the concept of collecting black frames that are not usedfor a main feature video and displaying subtitle data on the blackframes;

FIGS. 5A through 5C show the internal structure of the recording mediumin Embodiment 1.

FIGS. 6A and 6B show the internal structures of the main TS and sub-TS.

FIGS. 7A through 7D show the internal structures of the playlistinformation.

FIGS. 8A and 8B show one example of the basic stream selection table.

FIG. 9 shows the internal structure of the extension stream selectiontable.

FIGS. 10A through 10C show stream registration sequences in theextension stream selection table.

FIG. 11 shows plane overlaying in the case where video_shift_mode is setas “Keep”.

FIG. 12A shows plane overlaying in the case where video_shift_mode isset as “Up”, and FIG. 12B shows plane overlaying in the case wherevideo_shift_mode is set as “Down”.

FIG. 13 shows a constraint of the order of registering graphics streamsin a stream selection table in the case where the video shift mode isadded to the stream additional information of the stream selectioninformation;

FIG. 14 shows what elementary streams are demultiplexed from the main TSand the sub-TSs with use of the basic stream selection table and theextension stream selection table.

FIG. 15 shows stream numbers to be assigned in the 2D output mode andthe 3D output mode.

FIG. 16 shows the internal structure of the playback device.

FIGS. 17A and 17B show the internal structure of the PG decoder.

FIGS. 18A and 18B show the internal structure of the text subtitledecoder.

FIGS. 19A and 19B show decoder models of the IG decoder.

FIG. 20 shows a circuit structure for overlaying the outputs of thedecoder models and outputting the result in the 3D-LR mode.

FIG. 21 shows a circuit structure for overlaying the outputs of thedecoder models and outputting the result in the 1 plane+offset mode.

FIG. 22 shows the circuit structure for overlaying data output from thedecoder model and outputting the overlaid data in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode.

FIG. 23 shows the internal structures of the register set 203 and theplayback control unit.

FIG. 24 shows the bit assignment in PSR24.

FIGS. 25A and 25B show the bit assignment in PSR32.

FIG. 26 shows the playlist playback procedure.

FIG. 27 is a flow chart showing the procedure for determining thecurrent PG_text subtitle stream when playback condition is changed.

FIG. 28 is a flow chart showing a procedure of determination processingof upper or lower end playback type.

FIG. 29 is a flow chart showing the procedure for selecting a PG_textsubtitle stream that is optimum for the current playitem.

FIG. 30 is a flow chart showing the procedure which is to be executedwhen a stream change is requested by the set stream stereoscopic command(set stream SS command).

FIG. 31 is a flow chart showing the procedure which is to be executedwhen a stream change is requested by the set stream command or by a useroperation requesting a stream number change.

FIGS. 32A and 32B are flow charts showing the procedures for determiningthe current IG stream and the playback type thereof.

FIGS. 33A through 33C show what packet identifiers are output to thedemultiplexing unit by the combined stream registration sequence.

FIGS. 34A through 34C show what packet identifiers are output to thedemultiplexing unit by the combined stream registration sequence.

FIGS. 35A through 35C show the stream registration sequences in anextension stream selection table according to a modification example ofEmbodiment 1.

FIG. 36 shows the circuit structure for overlaying data output from thedecoder model and outputting the overlaid data in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode.

FIG. 37 shows a system parameter showing a shift amount of each plane inthe longitudinal axis direction;

FIG. 38 shows a method of shifting and cropping a PG plane in accordancewith a video shift mode;

FIG. 39 shows a constraint condition for disposing subtitle data in aregion that is not cropped in plane overlaying in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode;

FIG. 40 shows functions of an output offset correction value for thesense of depth influenced by each screen size of TV.

FIG. 41 shows a table in which inch types of TV to be stored in aplaylist file and output offset correction values are recorded;

FIG. 42 shows an example where images are displayed on a TV having thesize larger than the optimal inch size.

FIG. 43 shows the structure of a 2D/3D playback device for applying anoutput offset correction value;

FIG. 44 shows the structure in which an output offset correction valueand an output offset correction value α are applied;

FIG. 45 shows the correspondence between the file 2D/file base and thefile dependent.

FIGS. 46A through 46C show the correspondence between the interleavedstream file and file 2D/file base.

FIG. 47 shows correspondence among the stereoscopic interleaved streamfile, file 2D, file base, and file dependent.

FIG. 48 shows the 2D playlist and 3D playlist.

FIGS. 49A through 49D show the internal structure of the clipinformation file.

FIG. 50 shows the correspondence among the clip information file,playlist, and stereoscopic interleaved stream file.

FIGS. 51A and 51B show the internal structure of the clip baseinformation and the clip dependent information.

FIG. 52 shows the basic entry map and the extension entry map.

FIG. 53 shows entries that are not permitted in the extension entry map.

FIG. 54 is a flow chart showing the playitem playback procedure.

FIG. 55 shows how the ATC sequence is restored from the data blocksconstituting the stereoscopic interleaved stream file.

FIGS. 56A and 56B show how the ATC sequence is restored.

FIGS. 57A through 57D show one example of the extent start pointinformation table in the base-view clip information and one example ofthe extent start point information table in the dependent-view clipinformation.

FIGS. 58A through 58C are illustrations provided for explanation of thesource packet numbers of arbitrary data blocks in ATC sequences 1 and 2.

FIG. 59 shows the procedure for restoring the ATC sequence.

FIG. 60 shows a playback environment for a 2D/3D playback device;

FIG. 61 shows a case where only one of a right-eye video and a left-eyevideo is output during switching from playback 3D videos to 2D videoswithout switching a frame rate;

FIG. 62 shows the correlation between subtitles and streams for menuthat are used in BD or the like;

FIG. 63 shows processing for realizing more smooth 2D/3D video display;

FIGS. 64A and 64B show a manufacturing method of an optical disc.

FIG. 65 is a flow chart showing the procedure of the authoring step.

FIG. 66 is a flow chart showing the procedure for writing the AV file.

FIG. 67 is a flow chart showing the procedure for generating the basicentry map and the extension entry map.

FIG. 68 is a flow chart showing the procedure for generating the BD-Japplication, BD-J object, movie object, and index table.

FIG. 69 shows an internal structure of a multi-layered optical disc.

FIG. 70 shows the application format of the optical disc based on thefile system.

FIG. 71 shows the structure of a 2D/3D playback device.

FIGS. 72A through 72C show the embodiment of a usage act of a recordingmedium relating to the present invention, the structure of the BD-ROM,and the structure of the index file.

FIGS. 73A and 73B show the structure of an AV clip and how each streamis multiplexed in the AV clip.

FIGS. 74A and 74B illustrate in detail how the video stream is stored inthe PES packet series, and show the TS packets and source packets in theAV clip.

FIGS. 75A and 75B show the data structure of the PMT and the internalstructure of the clip information file.

FIGS. 76A and 76B show the internal structure of the stream attributeinformation and the internal structure of the entry map.

FIGS. 77A through 77C show the internal structure of the playlist andthe internal structure of the playitem.

FIGS. 78A and 78B show the structure of a 2D playback device and explainthe player variable.

FIG. 79 shows the internal structure of the system target decoder.

FIG. 80 illustrates the stereoscopic viewing.

FIG. 81 shows the data structure of a presentation graphics stream;

FIG. 82 shows decode processing of the presentation graphics stream;

FIG. 83 shows a method of storing a playlist of a shift value in videoshift upward and a shift value in video shift downward;

FIG. 84 shows the structure of plane overlaying performed by the 2D/3Dplayback device for performing video shift of collecting black frames inone of an upper side and a lower side;

FIG. 85 shows the structure of a playlist in which the video shift modeis added to stream additional information of stream selectioninformation;

FIG. 86 shows a plane overlaying method in the case where the videoshift mode has been added to the stream additional information of thestream selection information;

FIG. 87 shows, in the upper level, a method of creating a video streamby disposing a main feature video not on the center but on a slightlyupper side and, in the lower level, a method of creating a black frameby dynamically changing a transparent color of a PG stream;

FIGS. 88A and 88B show the structure in which each extent includes atleast one entry point.

FIGS. 89A and 89B show a method of storing offset metadata in an AVstream information file.

FIGS. 90A and 90B show a method of storing offset metadata for eachentry point.

FIGS. 91A and 91B show a method of storing offset metadata in aplaylist.

FIGS. 92A and 92B show, in the case where offset metadata is stored in aplaylist, a method of not storing offset metadata when a currentplayitem is the same as a previous playitem.

FIG. 93 shows, in the case where offset metadata is stored in aplaylist, a method of storing only the same one piece of offset metadatawith respect to a plurality of playitems having the same one piece ofoffset metadata.

FIG. 94 shows a playlist in which a header in units of playitems andoffset metadata are separately stored.

FIG. 95 shows a case where a left-eye graphics subtitle in the 2 planeL/R method is displayed as a 2D display subtitle.

FIG. 96 shows the 2D display subtitle and the 1 plane+offset methodsubtitle, and an offset value of PG for the 2 plane LR method forsharing the left-eye PG in the 2 plane LR method.

FIG. 97 shows the structure of separating a 2D/3D playback path in orderto increase in speed of jump playback;

FIG. 98 shows an example of an index file (Index.bdmv) stored in aBD-ROM for playing back stereoscopic images.

FIG. 99 is a flow chart showing switching between the playback of the 2DPlayList and the 3D PlayList of a program of a BD program file;

FIG. 100 shows an example structure of a 2D/3D playback device which isrealized by using an integrated circuit.

FIG. 101 is a functional block diagram showing a typical structure ofthe stream processing unit.

FIG. 102 is a conceptual diagram showing the switching unit and theperipheral when the switching unit is DMAC.

FIG. 103 is a functional block diagram showing a typical structure ofthe AV output unit.

FIG. 104 is an example structure showing the AV output unit, or the dataoutput part of the playback device in more detail.

FIG. 105 shows arrangement of control buses and data buses in theintegrated circuit.

FIG. 106 shows arrangement of control buses and data buses in theintegrated circuit.

FIG. 107 shows an example structure of a display device which isrealized by using an integrated circuit.

FIG. 108 is a functional block diagram showing a typical structure of anAV output unit of the display device.

FIG. 109 is a flow chart showing an operation procedure in the playbackdevice.

FIG. 110 is a flow chart showing a detailed operation procedure in theplayback device.

DESCRIPTION OF EMBODIMENTS

The recording media provided with the solution to problem describedabove may be implemented as package media containing contents for saleon a store. Also, playback devices supporting the recording media may beimplemented as player devices for playing back the package media, andintegrated circuits supporting the recording media may be implemented assystem LSIs to be embedded in the player devices.

FIGS. 1A through 1C show a home theater system that is composed of arecording medium being a package medium, a playback device being aplayer device, a display device, and glasses. As shown in FIG. 1A, arecording medium 100 being a package medium as described above and aplayback device 200 being a player device constitute the home theatersystem together with a display device 300, 3D glasses 400, and a remotecontrol 500. The home theater system structured as such is subject touse by the user.

The recording medium 100 provides the home theater system with, forexample, a movie work. The movie work may provide a stereoscopic image.Here, the stereoscopic image is composed of at least two view-pointimages. The view-point image is an image that is deflected to someextent, and the at least two view-point images include a main-view imageand a sub-view image. As shown in FIG. 1A, the recording medium 100 maybe, for example, a disc or a memory card among many types of recordingmedia. In the following, a “recording medium” is presumed to be a discunless otherwise noted.

The playback device 200 is connected with the display device 300 andplays back the recording medium 100. The playback device described inthe present application is a 2D/3D playback device (player) which,provided with the 2D output mode and the 3D output mode, can switchbetween these output modes to play back a main-view video streamrepresenting a main-view image and a sub-view video stream representinga sub-view image.

The display device 300 is a television and provides the user with aninteractive operation environment by displaying a menu and the like aswell as images of movie works. In the present embodiment, the user needsto wear the 3D glasses 400 for the display device 300 to realize thestereoscopic viewing. Here, the 3D glasses 400 are not necessary whenthe display device 300 displays images by the lenticular method.

The 3D glasses 400 are equipped with liquid-crystal shutters that enablethe user to view a parallax image by the sequential segregation methodor the polarization glasses method. Here, the parallax image is an imagewhich is composed of a pair of (i) an image that enters only into theright eye and (ii) an image that enters only into the left eye, suchthat pictures respectively associated with the right and left eyesrespectively enter the eyes of the user, thereby realizing thestereoscopic viewing. FIG. 1B shows the state of the 3D glasses 400 whenthe left-view image is displayed. At the instant when the left-viewimage is displayed on the screen, the liquid-crystal shutter for theleft eye is in the light transmission state, and the liquid-crystalshutter for the right eye is in the light block state. FIG. 1C shows thestate of the 3D glasses 400 when the right-view image is displayed. Atthe instant when the right-view image is displayed on the screen, theliquid-crystal shutter for the right eye is in the light transmissionstate, and the liquid-crystal shutter for the left eye is in the lightblock state.

The remote control 500 is a machine for receiving operations for playingback AV from the user. The remote control 500 is also a machine forreceiving operations onto the layered GUI from the user. To receive theoperations, the remote control 500 is equipped with a menu key, arrowkeys, an enter key, a return key, and numeral keys, where the menu keyis used to call a menu constituting the GUI, the arrow keys are used tomove a focus among GUI components constituting the menu, the enter keyis used to perform ENTER (determination) operation onto a GUI componentconstituting the menu, the return key or numeric keys are used to returnto a higher layer in the layered menu.

In the home theater system shown in FIGS. 1A through 1C, an output modeof the playback device for causing the display device 300 to displayimages in the 3D output mode is called a “3D output mode”, and an outputmode of the playback device for causing the display device 300 todisplay images in the 2D output mode is called a “2D output mode”.

This completes the description of the usage act of the recording mediumand the playback device.

Embodiment 1

Embodiment 1 is characterized in that a register in the playback devicestores information that indicates whether or not the playback device hasa capability to realize a stereoscopic viewing using a right-eyegraphics stream and a left-eye graphics stream.

In the following description, the main-view and the sub-view are used torealize the parallax image method. The parallax image method (alsocalled 3D-LR mode) is a method for realizing the stereoscopic viewing bypreparing separately an image for the right eye and an image for theleft eye, and causing the image for the right eye to enter only into theright eye and the image for the left eye enter only into the left eye.FIG. 2 shows the user's head on the left side of the drawing and theimages of a dinosaur skeleton seen respectively by the left eye and theright eye of the user on the right side of the drawing. When the lighttransmission and block are repeated alternately for the left and righteyes, the left and right scenes are overlaid in the brain of the user bythe effect of residual images of eyes, and the overlaid image isrecognized as a stereoscopic image appearing in front of the user.

The MPEG4-MVC method is used as the method for encoding the videostreams for realizing such a stereoscopic viewing. In the descriptionhereinafter it is presumed that the main-view video stream is “base-viewvideo stream” in the MPEG4-MVC method, and the sub-view video stream is“dependent-view video stream” in the MPEG4-MVC method.

The MPEG4-MVC base-view video stream is a sub-bit stream with view_idbeing set to “0”, and is a sequence of view components with view_idbeing set to “0”. The MPEG4-MVC base-view video stream conforms to therestrictions imposed on the MPEG4-AVC video stream.

The MPEG4-MVC dependent-view video stream is a sub-bit stream withview_id being set to “1”, and is a sequence of view components withview_id being set to “1”.

A view component is one of a plurality of pieces of picture data thatare played back simultaneously for the stereoscopic viewing in one frameperiod. A compress-encoding that makes use of the correlation betweenview points is realized by using, as picture data, view components ofthe base-view and dependent-view video streams to realize acompress-encoding that makes use of the correlation between pictures.View components of the base-view and dependent-view video streamsassigned to one frame period constitute one access unit. This makes itpossible for the random access to be performed in a unit of the accessunit.

Each of the base-view video stream and the dependent-view video streamhas a GOP structure in which each view component is a “picture”, and iscomposed of closed GOPs and open GOPs. The closed GOP is composed of anIDR picture, and B-pictures and P-pictures that follow the IDR picture.The open GOP is composed of a non-IDR I-picture, and B-pictures andP-pictures that follow the non-IDR I-picture.

The non-IDR I-pictures, B-pictures, and P-pictures are compress-encodedbased on the frame correlation with other pictures. The B-picture is apicture composed of slice data in the bidirectionally predictive (B)format, and the P-picture is a picture composed of slice data in thepredictive (P) format. The B-picture is classified into reference B (Br)picture and non-reference B (B) picture.

In the closed GOP, the IDR picture is disposed at the top. In thedisplay order, the IDR picture is not the top, but pictures (B-picturesand P-pictures) other than the IDR picture cannot have dependencyrelationship with pictures existing in a GOP that precedes the closedGOP. As understood from this, the closed GOP has a role to complete thedependency relationship.

FIG. 3 shows one example of the internal structures of the base-view anddependent-view video streams for the stereoscopic viewing.

The second row of FIG. 3 shows the internal structure of the base-viewvideo stream. This stream includes view components with picture typesI1, P2, Br3, Br4, P5, Br6, Br7, and P9. These view components aredecoded according to the Decode Time Stamps (DTS). The first row showsthe left-eye image. The left-eye image is played back by playing backthe decoded view components I1, P2, Br3, Br4, P5, Br6, Br7, and P9according to the PTS, in the order of I1, Br3, Br4, P2, Br6, Br7, andP5.

The fourth row of FIG. 3 shows the internal structure of thedependent-view video stream. This stream includes view components withpicture types P1, P2, B3, B4, P5, B6, B7, and P8. These view componentsare decoded according to the DTS. The third row shows the right-eyeimage. The right-eye image is played back by playing back the decodedview components P1, P2, B3, B4, P5, B6, B7, and P8 according to the PTS,in the order of P1, B3, B4, P2, B6, B7, and P5.

The fifth row of FIG. 3 shows how the state of the 3D glasses 400 ischanged. As shown in the fifth row, when the left-eye image is viewed,the shutter for the right eye is closed, and when the right-eye image isviewed, the shutter for the left eye is closed.

Here, a mode, in which video frames of the base-view video stream (B)and video frames of the dependent-view video stream (D) are alternatelyoutput at a display cycle of 1/48 seconds like “B”-“D”-“B”-“D”, iscalled a “B-D presentation mode”.

The B-D presentation mode includes a 3D-depth mode in which thestereoscopic viewing is realized by using the 2D images and depthinformation, as well as a 3D-LR mode in which the stereoscopic viewingis realized by using L (Left) images and R (Right) images.

Also, a mode, in which a same type of video frame is repeatedly outputtwice or more while the 3D mode is maintained as the output mode, iscalled a “B-B presentation mode”. In the B-B presentation mode, videoframes of an independently playable base-view video stream arerepeatedly output like “B”-“B”-“B”-“B”.

The B-D presentation mode and the B-B presentation mode described aboveare basic presentation modes in the playback device. Other than these,output modes such as a 1 plane+offset mode, an upper end 2D subtitleplayback mode, and a lower end 2D subtitle playback mode are availablein the playback device.

The 1 plane+offset mode (also referred to as “3D-offset mode”) is anoutput mode in which the stereoscopic viewing is realized byincorporating a shift unit at a location subsequent to the plane memoryand functioning the shift unit. In each of the left-view period and theright-view period, the plane offset unit shifts the coordinates of thepixels in the plane memory in units of lines leftward or rightward todisplace the image formation point of the right-eye and left-eye viewlines frontward or backward so that the viewer can feel a change in thesense of depth. More specifically, when the pixels coordinates areshifted leftward in the left-view period, and rightward in theright-view period, the image formation point is displaced frontward; andwhen the pixels coordinates are shifted rightward in the left-viewperiod, and leftward in the right-view period, the image formation pointis displaced backward.

In such a plane shift, the plane memory for the stereoscopic viewingonly needs to have one plane. It is thus the best method for generatingthe stereoscopic images with ease. However, the plane shift merelyproduces stereoscopic images in which monoscopic images come frontwardor go backward. Therefore, it is suited for generating a stereoscopiceffect for the menu or subtitle, but leaves something to be desired inrealizing a stereoscopic effect for the characters or physical objects.This is because it cannot reproduce dimples or unevenness of the facesof characters.

To support the 1 plane+offset mode, the playback device is structured asfollows. For the playback of graphics, the playback device includes aplane memory, a CLUT unit, and an overlay unit. The plane shift unit isincorporated between the CLUT unit and the overlay unit. The plane shiftunit realizes the above-described change of pixel coordinates by usingthe offset in the offset sequence incorporated in the access unitstructure of the dependent-view video stream. With this arrangement, thelevel of jump-out of pixels in the 1 plane+offset mode changes insynchronization with the MVC video stream. The 1 plane+offset modeincludes “1 plane+zero offset mode”. The 1 plane+zero offset mode is adisplay mode which, when the pop-up menu is ON, gives the stereoscopiceffect only to the pop-up menu by making the offset value zero.

The target of the shift control by the offset sequence is a plurality ofplane memories which constitute a predetermined layer model. The planememory is a memory for storing one screen of pixel data, which has beenobtained by decoding the elementary streams, in units of lines so thatthe pixel data can be output in accordance with the horizontal andvertical sync signals. Each of the plurality of plane memories storesone screen of pixel data that is obtained as a result of decoding by thevideo decoder, PG decoder, or IG decoder.

The predetermined layer model is composed of a layer of the left-eyevideo plane and the right-eye video plane, a layer of the PG plane, anda layer of the IG/BD-J plane, and is structured so that these layers(and the contents of the plane memories in these layers) can be overlaidin the order of the base-view video plane, PG plane, and IG/BD-J planefrom the bottom.

The layer overlay is achieved by executing a superimposing process ontoall combinations of the two layers in the layer model. In thesuperimposing process, pixel values of pixel data stored in the planememories of the two layers are superimposed. The following describes theplane memories in each layer.

The left-eye video plane is a plane memory for storing pixel dataconstituting the left-eye picture data among one screen of pixel datathat is obtained by decoding the view components. The right-eye videoplane is a plane memory for storing pixel data constituting theright-eye picture data among one screen of pixel data that is obtainedby decoding the view components.

The presentation graphics (PG) plane is a plane memory for storinggraphics that are obtained when a graphics decoder, which operates bythe pipeline method, performs the decoding process. The IG/BD-J plane isa plane memory that functions as an IG plane in some operation mode andfunctions as a BD-J plane in other operation mode. The interactivegraphics (IG) plane is a plane memory for storing graphics that areobtained when a graphics decoder, which operates based on theinteractive process, performs the decoding process. The BD-J plane is aplane memory for storing the drawing image graphics that are obtainedwhen an application of an object-oriented programming language performsthe drawing process. The IG plane and the BD-J plane are exclusive toeach other, and when one of them is used, the other cannot be used.Therefore the IG plane and the BD-J plane share one plane memory.

In the above-mentioned layer model, with regard to the video plane,there are a base-view plane and a dependent-view plane. On the otherhand, with regard to the IG/BD-J plane and the PG plane, there isneither a base-view plane nor a dependent-view plane. For this reason,the IG/BD-J plane and the PG plane are the target of the shift control.

The upper end 2D subtitle playback mode is an output mode in which adisplay region of a 2D subtitle is saved in the upper end of a videoframe by incorporating a shift unit at a location subsequent to thevideo plane memory and causing the shift unit to function. The lower end2D subtitle playback mode is an output mode in which a display region ofa 2D subtitle is saved in the lower end of a video frame by causing theshift unit to function. In the upper end 2D subtitle playback mode, theplane offset unit shifts downward pixel coordinates of picture datastored in the video plane memory during each of the left-view period andthe right-view period. In the lower end 2D subtitle playback mode, theplane offset unit shifts upward the pixel coordinates of the picturedata stored in the video plane memory during each of the left-viewperiod and the right-view period.

In order to support the upper end 2D subtitle playback mode and thelower end 2D subtitle playback mode, the playback device needs to bestructured as follows. The playback device includes a video plane memoryand an overlay unit for playback of video frames and graphics, andfurther includes a shift unit incorporated between the video planememory and the overlay unit. The shift unit realizes the change of pixelcoordinates as described above, using an offset incorporated into astream registration sequence of a graphics stream.

FIG. 4A shows a video frame suitable for use in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode. Inthe figure, an image of a cinema scope size having an aspect ratio of2.35:1 and a resolution of 1920×818 pixels is disposed in the center ofa screen having an aspect ratio of 16:9 and a resolution of 1920×1080pixels. A black frame having 1920×131 pixels is disposed in each of theupper end and the lower end of the image of the cinema scope size. Inthe video plane memory in which such a video frame is stored, pixelcoordinates are shifted upward or downward, and black color data isstored in a blank region obtained by the shifting. As a result, theblack frames that have been originally disposed in the upper and lowerends are collected in either the upper end or the lower end, as shown inFIGS. 4B and 4C. As a result, it is possible to prepare a black frameenough large to display subtitles.

This completes the explanation of the 3D output mode. The followingexplains the internal structure of the recording medium pertaining tothe present embodiment.

FIGS. 5A through 5C show the internal structure of the recording mediumin Embodiment 1. As shown in FIG. 5A, the recording medium in Embodiment1 stores an “index table”, an “operation mode object program file”, a“playlist information file”, a “stream information file”, and a “streamfile”.

<Index Table>

The index table is management information of the entire recordingmedium. The index table is read first by a playback device after therecording medium is loaded into the playback device, thereby therecording medium is uniquely identified by the playback device.

<Program File>

The program file of the operation mode object stores control programsfor operating the playback device. The control program may be written asa set of commands or written in an object-oriented compiler language.The former program supplies a plurality of navigation commands as abatch job to the playback device in the command-based operation mode tooperate the playback device based on the navigation commands. Thecommand-based operation mode is called an “HDMV mode”.

The latter program supplies bytecode applications, which are instancesof class structure, to the playback device in the operation mode whichis based on the object-oriented compiler language, in order to operatethe playback device based on the instances. Java™ applications, whichare one of the bytecode applications, can be used as the instances ofclass structure. The operation mode based on the object-orientedcompiler language is called a “BD-J mode”.

<Stream File>

A stream file stores a transport stream that is obtained by multiplexinga video stream, one or more audio streams, and a graphics stream. Thestream file has two types: 2D-only; and 2D/3D shared. The 2D-only streamfile is in a normal transport stream format. The 2D/3D shared streamfile is in a stereoscopic interleaved stream file format.

The stereoscopic interleaved stream file format is a file format inwhich Extents of a main transport stream (main TS) including a base-viewstream and Extents of a sub transport stream (sub TS) including adependent-view stream are arranged in an interleaved manner.

The main TS stored in the stream file contains packet managementinformation (PCR, PMT, PAT) defined in the European digital broadcaststandard, as information for managing and controlling a plurality oftypes of PES streams.

The PCR (Program Clock Reference) stores STC time informationcorresponding to an ATS that indicates the time when the PCR packet istransferred to a decoder, in order to achieve synchronization between anATC (Arrival Time Clock) that is a time axis of ATSs, and an STC (SystemTime Clock) that is a time axis of PTSs and DTSs.

The PMT (Program Map Table) stores PIDs in the streams of video, audio,graphics and the like contained in the transport stream file, andattribute information of the streams corresponding to the PIDs. The PMTalso has various descriptors relating to the TS. The descriptors haveinformation such as copy control information showing whether copying ofthe AV clip is permitted or not.

The PAT (Program Association Table) shows a PID of a PMT used in the TS,and is registered by the PID arrangement of the PAT itself.

These PCR, PMT, and PAT, in the European digital broadcast standard,have a role of defining partial transport streams constituting onebroadcast program (one program). This enables the playback device tocause the decoder to decode TSs as if it deals with the partial TSsconstituting one broadcast program, conforming to the European digitalbroadcast standard. This structure is aimed to support compatibilitybetween the recording medium playback devices and the terminal devicesconforming to the European digital broadcast standard.

Pair of extents in the main TS and the sub-TS are each set to have adata size such that underflow of double buffer is not occurred duringplayback. This enables the playback device to load these pairs ofextents without interruption.

This completes the description of the stream file.

<Stream Information File>

The stream information file is a file for ensuring a random access toany source packet in a transport stream stored in a stream file, andensuring a seamless playback with other transport streams. Via thestream information files, the stream files are managed as “AV clips”.The stream information file includes information of the AV clip such asthe stream encoding format, frame rate, bit rate, and resolution, andincludes a basic entry map that shows correspondence between sourcepacket numbers at the starts of GOPs and the presentation time stamps inthe frame periods. Thus, by preloading the stream information file priorto an access to the stream file, the property of the transport stream inthe stream file to be accessed is recognized, thereby the execution ofthe random access is ensured. The stream information file has two types:2D stream information file; and 3D stream information file. The 3Dstream information file includes clip information for the base view(clip base information), clip information for the dependent view (clipdependent information), and an entry map extended for the stereoscopicviewing.

The clip base information includes base-view extent start pointinformation, and the clip dependent information includes dependent-viewextent start point information. The base-view extent start pointinformation includes a plurality of source packet numbers. Each sourcepacket number indicates a packet number of a packet including a boundarybetween Extents in the main TS. The dependent-view extent start pointinformation also includes a plurality of source packet numbers. Eachsource packet number indicates a packet number of a packet including aboundary between Extents in the sub-TS. By using these extent startpoint information, the stereoscopic interleaved stream file is dividedinto an ATC sequence 1 constituting the main TS and an ATC sequence 2constituting the sub-TS. The ATC sequence is a sequence of sourcepackets, wherein Arrival_Time_Clocks referred to by theArrival_Time_Stamps included in the ATC sequence includes “no arrivaltime-base discontinuity”. Since the ATC sequence is a sequence of sourcepackets in which the ATC time stamps are continuous, each source packetconstituting the ATC sequence is subjected to continuous source packetdepacketizing processes and continuous packet filtering processes whilethe clock counter is counting the arrival time clocks of the playbackdevice.

While the ATC sequence is a sequence of source packets, a sequence of TSpackets whose time stamps are continuous in the STC time axis is calledan “STC sequence”. The STC sequence is a sequence of TS packets which donot include “system time-base discontinuity”, which is based on the STC(System Time Clock) that is a system standard time for TSs. The presenceof the system time-base discontinuity is indicated by a“discontinuity_indicator” being ON, where the discontinuity_indicator iscontained in a PCR packet carrying a PCR (Program Clock Reference) thatis referred to by the decoder to obtain an STC. The STC sequence is asequence of TS packets whose time stamps are continuous in the STC timeaxis. Therefore, each TS packet constituting the STC sequence issubjected to continuous decoding processes performed by the decoderprovided in the playback device, while the clock counter is counting thesystem time clocks of the playback device. The extension entry mapindicates, in correspondence with the presentation time stampsrepresenting the frame periods at the starts of GOPs, source packetnumbers of access unit delimiters which indicate starting positions ofview components at the starts of GOPs in the dependent-view videostream.

On the other hand, the basic entry map in the 3D stream information fileindicates, while maintaining the compatibility with the 2D streaminformation file, in correspondence with the presentation time stampsrepresenting the frame periods at the starts of GOPs, source packetnumbers of access unit delimiters which indicate starting positions ofview components at the starts of GOPs in the base-view video stream.

<Playlist Information File>

The playlist information file is a file storing information that is usedto cause the playback device to play back a playlist. The “playlist”indicates a playback path defined by logically specifying a playbackorder of playback sections, where the playback sections are defined on atime axis of transport streams (TS). The playlist has a role of defininga sequence of scenes to be displayed in order, by indicating which partsof which transport streams among a plurality of transport streams shouldbe played back. The playlist 1 information defines “patterns” of theplaylists. The playback path defined by the playlist information is whatis called a “multi-path”. The multi-path is composed of a “main path”and one or more “sub-paths”. The main path is defined for the maintransport streams. The sub-paths are defined for sub streams. Aplurality of sub-paths can be defined while one main path is defined. Bydefining a playback path of the base-view video stream in the main pathand defining a playback path of the dependent-view video stream in thesub-path, it is possible to suitably define a set of video streams forperforming a stereoscopic playback.

AV playback by the multi-path can be started when the application of anobject-oriented programming language instructs to generate a frame workplayer instance that plays back the playlist information. The frame workplayer instance is actual data that is generated on the heap memory ofthe virtual machine based on the media frame work player class. Also,arrangement may be made so that playback by the multi-path can bestarted when a command-based program issues a playback command with anargument specifying the playlist information.

The playlist information includes one or more pieces of playiteminformation. The playitem information is playback section informationthat defines one or more pairs of an “in_time” time point and an“out_time” time point on the video stream playback time axis.

The playlist information has a hierarchical structure composed ofplayitem information, clip information, and a transport stream. It ispossible to set a one-to-many relationship between (i) a pair oftransport stream and clip information and (ii) playitem information sothat one transport stream can be referenced by a plurality of pieces ofplayitem information. This makes it possible to adopt, as a bank film, atransport stream created for a title so that the bank film can bereferenced by a plurality of pieces of playitem information in aplurality of playlist information files, making it possible to create aplurality of variations of a movie effectively. Note that the “bankfilm” is a term used in the movie industry and means an image that isused in a plurality of scenes.

In general, the users do not recognize the unit called playlist, andrecognize a plurality of variations (for example, a theatrical versionand a TV broadcast version) branched from the stream files as theplaylists.

The playlist information falls into two types: 2D playlist information;and 3D playlist information. A difference between them is that the 3Dplaylist information includes a base-view indicator and a stereoscopicstream selection table.

The “stereoscopic stream selection table” is a table that shows, incorrespondence with stream numbers, stream attributes and stream entriesof elementary streams that are to be played back only in the 3D outputmode.

The “base-view indicator” is information indicating either the left eyeor the right eye for which the base-view video stream is to beindicated, wherein the base-view video stream is the base of thecompress-encoding using the correlation between view points. By changingthe base-view indicator of the playlist information, it is possible tochange the assignment of the left eye and right eye at the level of theplaylist.

Since the assignment of the left eye and right eye can be changed at thelevel of the playlist that does not depend on the structure of thestream, when, for example, there is a playlist in which the position andangle of an object in the image is set as “base view=left eye” and“dependent view=right eye”, it is possible to generate a playlist inwhich the position and angle of an object in the image is set as “baseview=right eye” and “dependent view=left eye”, as another version.

By reversing the assignment of the left eye and right eye to thebase-view and dependent-view video streams at the level of the playlist,it is possible to reverse the stereoscopic effect. For example, whenthere has already been generated a playlist intending a stereoscopiceffect that the object appears in front of the screen, it is possible togenerate another playlist intending a stereoscopic effect that theobject appears behind the screen. This produces an advantageous effectthat variations of 3D playlists with different stereoscopic effects canbe generated easily.

FIG. 5B shows the internal structure of the main TS. FIG. 5C shows theinternal structure of the sub-TS. As shown in FIG. 5B, the main TSincludes one base-view video stream, 32 base-view PG streams, 32base-view IG streams, and 32 audio streams. As shown in FIG. 5C, thesub-TS includes one dependent-view video stream, 32 dependent-view PGstreams, and 32 dependent-view IG streams.

Next, the internal structure of TS will be described.

The elementary streams (ES) to be multiplexed in the TSs include thevideo stream, audio stream, presentation graphics stream, andinteractive graphics stream.

(Video Stream)

The base-view video stream constitutes a primary video stream in apicture-in-picture application. The picture-in-picture application iscomposed of the primary video stream and a secondary video stream. Theprimary video stream is a video stream composed of picture data of thepicture-in-picture application that represents a parent picture in thescreen; and the secondary video stream is a video stream composed ofpicture data of the picture-in-picture application that represents achild picture that is fit in the parent picture.

The picture data constituting the primary video stream and the picturedata constituting the secondary video stream are stored in differentplane memories after being decoded. The plane memory that stores thepicture data constituting the secondary video stream has, in the firsthalf thereof, a structural element (Scaling & Positioning) that performschanging scaling of the picture data constituting the secondary videostream, and positioning display coordinates of the picture dataconstituting the secondary video stream.

(Audio Stream)

The audio stream is classified into two types of a primary audio streamand a secondary audio stream.

The primary audio stream is an audio stream that is to be a main audiowhen the mixing playback is performed; and the secondary audio stream isan audio stream that is to be a sub-audio when the mixing playback isperformed. The secondary audio stream includes information fordownsampling for the mixing, and information for the gain control.

(Presentation Graphics (PG) Stream)

The PG stream is a graphics stream that can be synchronized closely withthe video, with the adoption of the pipeline in the decoder, and issuited for representing subtitles. The PG stream falls into two types: a2D PG stream; and a stereoscopic PG stream. The stereoscopic PG streamfurther falls into two types: a left-eye PG stream; and a right-eye PGstream.

It is possible to define up to 32 2D PG streams, up to 32 left-eye PGstreams, and up to 32 right-eye PG streams. These PG streams areattached with different packet identifiers. Thus, it is possible tocause a desired PG stream among these PG streams to be subjected to theplayback, by specifying a packet identifier of the one to be played backto the demultiplexing unit.

Close synchronization with video is achieved due to the decoding withthe pipeline adopted therein. Thus the use of the PG stream is notlimited to the playback of characters such as the subtitle characters.For example, it is possible to display a mascot character of the moviethat is moving in synchronization with the video. In this way, anygraphics playback that requires close synchronization with the video canbe adopted as a target of the playback by the PG stream.

The PG stream is a stream that is not multiplexed into the transportstream but represents a subtitle. The text subtitle stream (alsoreferred to as a “textST stream”) is a stream of this kind, as well. ThetextST stream is a stream that represents the contents of subtitle bythe character codes.

The PG stream and the text subtitle stream are registered as the samestream type in the same stream registration sequence, withoutdistinction between them in type. And then during execution of aprocedure for selecting a stream, a PG stream or a text subtitle streamto be played back is determined according to the order of streamsregistered in the stream registration sequence. In this way, the PGstreams and text subtitle streams are subjected to the stream selectionprocedure without distinction between them in type. Therefore, they aretreated as belonging to a same stream type called “PG_text subtitlestream”.

The PG_text subtitle stream for 2D is played back in the 1 plane+offsetmode, the upper end 2D subtitle playback mode, and the lower end 2Dsubtitle playback mode.

(Interactive Graphics (IG) Stream)

The IG stream is a graphics stream which, having information forinteractive operation, can display menus with the progress of playbackof the video stream and display pop-up menus in accordance with useroperations.

As is the case with the PG stream, the IG stream is classified into twotypes of a 2D IG stream and a stereoscopic IG stream. The IG streamcontrol information (called “interactive control segment”) includesinformation (user_interface_model) that defines the user interfacemodel. The person in charge of authoring can specify either “always on”or “pop-up menu on” by setting the user interface model information,where with the “always on”, menus are displayed with the progress ofplayback of the video stream, and with the “pop-up menu on”, the pop-upmenus are displayed in accordance with user operations.

The interactive operation information in the IG stream has the followingmeaning. When the Java™ virtual machine instructs the playback controlengine, which is proactive in the playback control, to start playingback a playlist in accordance with a request from an application, theJava™ virtual machine, after instructing the playback control engine tostart the playback, returns a response to the application to notify thatthe playback of the playlist has started. That is to say, while theplayback of the playlist by the playback control engine continues, theJava™ virtual machine does not enter the state waiting for end ofexecution. This is because the Java™ virtual machine is what is calledan “event-driven-type” performer, and can perform operation while theplayback control engine is playing back the playlist.

On the other hand, when, in the HDMV mode, the command interpreterinstructs the playback control engine to play back a playlist, it entersthe wait state until the execution of playback of the playlist ends.Accordingly, the command execution unit cannot execute an interactiveprocess while the playback of the playlist by the playback controlengine continues. The graphics decoder performs an interactive operationin place of the command interpreter. Thus, to cause the graphics decoderto perform the interactive operation, the IG stream is embedded withcontrol information defining interactive operations for which buttonsare used.

(Display Modes Allowed for Each Stream Type)

Different 3D display modes are allowed for each stream type. In theprimary video stream 3D display mode, two output modes, namely the B-Dpresentation mode and the B-B presentation mode are allowed. The B-Bpresentation mode is allowed for the primary video stream only when thepop-up menu is on. The type of primary video stream when the playback isperformed in the B-D presentation mode is called a “stereoscopic B-Dplayback type”. The type of primary video stream when the playback isperformed in the B-B presentation mode is called a “stereoscopic B-Bplayback type”.

In the PG stream 3D display mode, five output modes, namely the B-Dpresentation mode, 1 plane+offset mode, “1 plane+Zero Offset” mode,upper end 2D subtitle playback mode, and lower end 2D subtitle playbackmode are allowed. The “1 plane+zero offset” mode is allowed for the PGstream only when the pop-up menu is on. The type of PG stream when theplayback is performed in the B-D presentation mode is called a“stereoscopic playback type”. The type of PG stream and PG_text subtitlestream when the playback is performed in the 1 plane+offset mode iscalled a “1 plane+offset type”. The type of PG stream and PG_textsubtitle stream when the playback is performed in the “1 plane+zerooffset” mode is called a “1 plane+zero offset type”. A type of a PGstream or a text subtitle stream that is played back in the upper end 2Dsubtitle playback mode is referred to as an “upper end 2D subtitleplayback type”. A type of a PG stream or a text subtitle stream that isplayed back in the lower end 2D subtitle playback mode is referred to asa “lower end 2D subtitle playback type”.

In the text subtitle stream 3D display mode, four output modes, namelythe 1 plane+offset mode, the “1 plane+zero offset”, upper end 2Dsubtitle playback mode, and lower end 2D subtitle playback mode areallowed. The “1 plane+zero offset” mode is allowed for the text subtitlestream only when the pop-up menu is on.

In the IG stream 3D display mode, three output modes, namely the B-Dpresentation mode, 1 plane+offset mode, and “1 plane+zero offset” modeare allowed. The “1 plane+zero offset” mode is allowed for the IG streamonly when the pop-up menu is on. It is supposed in the followingdescription, except where otherwise mentioned, that thepicture-in-picture cannot be used during playback in the 3D output mode.This is because each of the picture-in-picture and the 3D output moderequires two video planes for storing non-compressed picture data. It isalso supposed in the following description, except where otherwisementioned, that the sound mixing cannot be used in the 3D output mode.

Next, the internal structures of the main TS and sub-TS will bedescribed. FIGS. 6A and 6B show the internal structures of the main TSand sub-TS.

FIG. 6A shows the internal structure of the main TS. The main TS iscomposed of the following source packets.

A source packet having packet ID “0x0100” constitutes aProgram_Map_Table (PMT). A source packet having packet ID “0x0101”constitutes a PCR.

A source packet sequence having packet ID “0x1011” constitutes theprimary video stream.

Source packet sequences having packet IDs “0x1200” through “0x121F”constitute 32 2D PG streams.

Source packet sequences having packet IDs “0x1400” through “0x141F”constitute 32 2D IG streams.

Source packet sequences having packet IDs “0x1100” through “0x111F”constitute primary audio streams.

By specifying a packet identifiers of one of these source packets to thedemultiplexing unit, it is possible to cause a desired elementary streamamong a plurality of elementary streams multiplexed in the maintransport streams to be demultiplexed and subjected to the decoder.

FIG. 6B shows the internal structure of the sub-TS. The sub-TS iscomposed of the following source packets.

A source packet sequence having packet ID “0x1012” constitutes thedependent-view video stream.

Source packet sequences having packet IDs “0x1220” through “0x123F”constitute 32 left-eye PG streams.

Source packet sequences having packet IDs “0x1240” through “0x125F”constitute 32 right-eye PG streams.

Source packet sequences having packet IDs “0x1420” through “0x143F”constitute 32 left-eye IG streams.

Source packet sequences having packet IDs “0x1440” through “0x145F”constitute 32 right-eye IG streams.

This completes the description of the stream file. Next is a detailedexplanation of the playlist information.

To define the above-described multi-path, the internal structures shownin FIGS. 7A through 7D are provided. FIG. 7A shows the internalstructure of the playlist information. As shown in FIG. 7A, the playlistinformation includes main-path information, sub-path information,playlist mark information, and extension data. These constitutionalelements will be described in the following.

1) The main-path information is composed of one or more pieces of mainplayback section information. FIG. 7B shows the internal structures ofthe main-path information and the sub-path information. As shown in FIG.7B, the main-path information is composed of one or more pieces of mainplayback section information, and the sub-path information is composedof one or more pieces of sub playback section information.

The main playback section information, called playitem information, isinformation that defines one or more logical playback sections bydefining one or more pairs of an “in_time” time point and an “out_time”time point on the TS playback time axis. The playback device is providedwith a playitem number register storing the playitem number of thecurrent playitem. The playitem being played back currently is one of theplurality of playitems whose playitem number is currently stored in theplayitem number register.

FIG. 7C shows the internal structure of the playitem information. Asshown in FIG. 7C, the playitem information includes stream referenceinformation, in-time out-time information, connection state information,and a basic stream selection table.

The stream reference information includes: “stream Information file nameinformation (clip_Information_file_name)” that indicates the file nameof the stream information file that manages, as “AV clips”, thetransport streams constituting the playitem; “clip encoding methodidentifier (clip_codec_identifier)” that indicates the encoding methodof the transport stream; and “STC identifier reference(STC_ID_reference)” that indicates STC sequences in which in-time andout-time are set, among the STC sequences of the transport stream.

This completes description of the playitem information.

2) The sub playback section information, called sub-path information, iscomposed of a plurality of pieces of sub-playitem information. FIG. 7Dshows the internal structure of the sub-playitem information. As shownin FIG. 7D, the sub-playitem information is information that definesplayback sections by defining pairs of an “in_time” and an “out_time” onthe STC sequence time axis, and includes stream reference information,in-time out-time information, sync playitem reference, and sync starttime information.

The stream reference information, as in the playitem information,includes: “stream Information file name information”, “clip encodingmethod identifier”, and “STC identifier reference”.

The “in-time out-time information (SubPlay_Item_In_Time,SubPlayItem_Out_Time)” indicates the start point and end point of thesub-playitem on the STC sequence time axis.

The “sync start time information (Sync_Start_PTS_of_Playitem)” indicatesa time point on the STC sequence time axis of the playitem specified bythe sync playitem identifier, that corresponds to the start point of thesub-playitem specified by the sub-playitem In_Time. The sub-playitemIn_Time exists on playback time axis of the playitem specified by thissync playitem identifier.

The “sync start time information (Sync_Start_PTS_of_Playitem)” indicatesa time point on the STC sequence time axis of the playitem specified bythe sync playitem identifier, that corresponds to the start point of thesub-playitem specified by the sub-playitem In_Time.

3) The playlist mark information is information that defines the markpoint unique to the playback section. The playlist mark informationincludes an indicator indicating a playback section, a time stampindicating the position of a mark point on the time axis of the digitalstream, and attribute information indicating the attribute of the markpoint.

The attribute information indicates whether the mark point defined bythe playlist mark information is a link point or an entry mark.

The link point is a mark point that can be linked by the link command,but cannot be selected when the chapter skip operation is instructed bythe user.

The entry mark is a mark point that can be linked by the link command,and can be selected even if the chapter skip operation is instructed bythe user.

The link command embedded in the button information of the IG streamspecifies a position for a random-access playback, in the form of anindirect reference via the playlist mark information.

<Basic Stream Selection Table (StreamNumber_table)>

The basic stream selection table shows a list of elementary streams thatare to be played back in a monoscopic output mode, and the table, when aplayitem containing the basic stream selection table itself becomes thecurrent playitem among a plurality of playitems constituting theplaylist, specifies, for each of the plurality of stream types, an ESwhich is permitted to be played back, among ESs multiplexed in AV clipsreferenced by the main path and the sub-path of the multi-path. Here,the stream types include: the primary video stream in thepicture-in-picture; the secondary video stream in thepicture-in-picture; the primary audio stream in the sound mixing; thesecondary audio stream in the sound mixing; the PG_text subtitle stream;and the IG stream. It is possible to register an ES which is permittedto be played back, for each of these stream types. More specifically,the basic stream selection table is composed of sequences of streamregistrations Here, the stream registration is information that, when aplayitem containing the basic stream selection table itself becomes thecurrent playitem, indicates what kind of stream is the ES permitted tobe played back. Each stream registration is associated with the streamnumber of the stream. Each stream registration has a data structure inwhich a pair of a stream entry and a stream attribute is associated witha logical stream number.

The stream number in the stream registration is represented by aninteger such as “1”, “2”, or “3”. The largest stream number for a streamtype is identical with the number of streams for the stream type.

The playback device is provided with a stream number register for eachstream type, and the current stream, namely the ES being played backcurrently, is indicated by the stream number stored in the stream numberregister.

A packet identifier of the ES to be played back is written in the streamentry. By making use of this structure in which a packet identifier ofthe ES to be played back can be written in the stream entry, the streamnumbers included in the stream registrations are stored in the streamnumber registers of the playback device, and the playback device causesthe PID filter thereof to perform a packet filtering based on the packetidentifiers stored in the stream entries of the stream registrations.With this structure, TS packets of the ESs that are permitted to beplayed back according to the basic stream selection table are output tothe decoder, so that the ESs are played back.

In the basic stream selection table, the stream registrations arearranged in an order of stream numbers. When there are a plurality ofstreams that satisfy the conditions: “playable by playback device”; and“the language attribute of the stream matches the language setting inthe device”, a stream corresponding to the highest stream number in thestream registration sequences is selected.

With this structure, when there is found a stream that cannot be playedback by the playback device, among the stream registrations in the basicstream selection table, the stream is excluded from the playback. Also,when there are a plurality of streams that satisfy the conditions:“playable by playback device”; and “the language attribute of the streammatches the language setting in the device”, the person in charge ofauthoring can convey the playback device how to select one with priorityfrom among the plurality of streams.

It is judged whether there is a stream that satisfies the conditions:“playable by playback device”; and “the language attribute of the streammatches the language setting in the device”. Also, a stream is selectedfrom among a plurality of streams that satisfy the conditions. Theprocedure for the judgment and selection is called “stream selectionprocedure”. The stream selection procedure is executed when the currentplayitem is switched, or when a request to switch the stream is input bythe user.

A sequential procedure for performing the above-described judgment andselection and setting a stream number in the stream number register ofthe playback device when a state change occurs in the playback device,such as when the current playitem is switched, is called “procedure tobe executed at state change”. Since the stream number registers areprovided respectively in correspondence with the stream types, theabove-described procedure is executed for each stream type.

A sequential procedure for performing the above-described judgment andselection and setting a stream number in the stream number register ofthe playback device when a request to switch the stream is input by theuser is called “procedure at state change request”.

A procedure for setting the stream number registers to the initialvalues of the stream registration sequences when a BD-ROM is loaded, iscalled “initialization”.

Priorities are assigned evenly to the streams specified in thesub-playitem information and the streams specified in the playiteminformation, as indicated by the stream registration sequences in thebasic stream selection table. As a result, even a stream not multiplexedwith a video stream is targeted for selection as a stream to be playedback in sync with the video stream, if the stream is specified by thesub-playitem information.

Furthermore, when playback device can play back a stream specified bythe sub-playitem information, and when the priority of the streamspecified by the sub-playitem information is higher than the priority ofthe graphics stream multiplexed with the video stream, the streamspecified by the sub-playitem information is played back in place of thestream multiplexed with the video stream.

The following explains the use of the stream numbers recited in thebasic stream selection table. The stream numbers recited in the basicstream selection table can be used as operands of the set streamcommand.

The set stream command is a command that instructs the playback deviceto change the current stream by setting the stream number specified bythe operand into the stream number register as the current streamnumber. The set stream command is used by a command-based program whenit causes the playback device to change the stream.

The set stream command can be used as an argument of the stream changeUO or an argument of the set stream API, as well. The stream change UOis a user operation event that instructs the playback device to changethe current stream by setting the stream number specified by theargument into the stream number register as the current stream number.

The set stream API is an API that instructs the playback device tochange the current stream by setting the stream number specified by theargument into the stream number register as the current stream number.The set stream API is used by a program based on an object-orientedprogramming language when it causes the playback device to change thestream.

FIGS. 8A and 8B show one example of the basic stream selection table.FIG. 8A shows a plurality of stream registration sequences that areprovided in the basic stream selection table when there are followingstream types: primary video stream; primary audio stream; PG stream; IGstream; secondary video stream; and secondary audio stream. FIG. 8Bshows the elementary streams that are demultiplexed from the main TS andthe sub-TSs with use of the basic stream selection table. The left sideof FIG. 8B shows the main TS and the sub-TSs, the middle part of FIG. 8Bshows the basic stream selection table and the demultiplexing unit, andthe right side of FIG. 8B shows the primary video stream, primary audiostream, PG stream, IG stream, secondary video stream, and secondaryaudio stream that are demultiplexed based on the basic stream selectiontable.

Next, the extension data will be described in detail.

When the playlist information refers to the MVC video stream, anextension stream selection table needs to be stored in a data block ofextension data in the playlist information file.

When the playlist information refers to the MVC video stream on thedisc, or the MVC video stream in the stereoscopic IG stream playbackmenu, extension information of the sub-path information (sub-path blockextension) needs to be stored in a data block of extension data in theplaylist information file.

When a 2D playback device finds unknown extension data in the playlistfile, the 2D playback device should disregard the extension data.

<Extension Stream Selection Table (StreamNumber_table_StereoScopic(SS))>

The extension stream selection table shows a list of elementary streamsthat are to be played back in a stereoscopic output mode, and is usedtogether with the basic stream selection table only in the stereoscopicoutput mode. The extension stream selection table defines the elementarystreams that can be selected when a playitem is played back or when asub-path related to the playitem is played back.

The extension stream selection table indicates the elementary streamsthat are permitted to be played back only in the stereoscopic outputmode, and includes stream registration sequences. Each piece of streamregistration information in the stream registration sequences includes astream number, and a stream entry and a stream attribute correspondingto the stream number. The extension stream selection table means anextension that is unique to the stereoscopic output mode. Therefore, aplaylist for which each piece of playitem information is associated withthe extension stream selection table (STN_table_SS) is called “3Dplaylist”.

Each stream entry in the extension stream selection table indicates apacket identifier that is to be used in the demultiplexing by theplayback device, when the playback device is in the stereoscopic outputmode, and the corresponding stream number is set in the stream numberregister of the playback device. A difference from the basic streamselection table is that the stream registration sequences in theextension stream selection table are not targeted by the streamselection procedure. That is to say, the stream registration informationin the stream registration sequences of the basic stream selection tableis interpreted as the priorities of the elementary streams, and a streamnumber in any piece of stream registration information is written intothe stream number register. In contrast, the stream registrationsequences of the extension stream selection table are not targeted bythe stream selection procedure, and the stream registration informationof the extension stream selection table is used only for the purpose ofextracting a stream entry and a stream attribute that correspond to acertain stream number when the certain stream number is stored in thestream number register.

Suppose that, when the output mode switches from the 2D output mode tothe 3D output mode, the target stream selection table also switches fromthe basic stream selection table to the extension stream selectiontable. Then, the identity of the stream numbers may not be maintained,and the identity of the language attribute may be lost, as well.

Accordingly, the use of the extension stream selection table isrestricted to the above-described one to maintain the identity of thestream attribute such as the language attribute.

The following explains the use of the stream numbers recited in theextension stream selection table. The stream numbers recited in theextension stream selection table can be used as operands of the setstream command and the set stereoscopic stream command.

The set stereoscopic stream command is a command that instructs theplayback device to change the current stream by setting the streamnumber for stereoscopic viewing specified by the operand into the streamnumber register as the current stream number. The set stereoscopicstream command is used by a command-based program when it causes theplayback device to change the stereoscopic stream.

The set stereoscopic stream command can be used as an argument of thestream change UO or an argument of the set stream API, as well.

The extension stream selection table is composed of stream registrationsequences of the dependent-view streams, stream registration sequencesof the PG streams, and stream registration sequences of the IG streams.

The stream registration sequences in the extension stream selectiontable are combined with the stream registration sequences of the samestream types in the basic stream selection table. More specifically, thedependent-view video stream registration sequences in the extensionstream selection table are combined with the primary video streamregistration sequences in the basic stream selection table; the PGstream registration sequences in the extension stream selection tableare combined with the PG stream registration sequences in the basicstream selection table; and the IG stream registration sequences in theextension stream selection table are combined with the IG streamregistration sequences in the basic stream selection table.

After this combination, the above-described procedure is executed ontothe stream registration sequences in the basic stream selection tableamong the two tables after the combination.

FIG. 9 shows the internal structure of the extension stream selectiontable. The extension stream selection table is composed of: “length”which indicates the entire length of the extension stream selectiontable; “fixed offset during pop-up (Fixed_offset_during_Popup)”; and thestream registration sequences of each stream type corresponding to eachplayitem.

When there are N pieces of playitems identified as playitems #1-#N,stream registration sequences respectively corresponding to theplayitems #1-#N are provided in the extension stream selection table.The stream registration sequences corresponding to each playitem aredependent-view stream registration sequence, PG stream registrationsequence, and IG stream registration sequence.

The “Fixed_offset_during_Popup” is a fixed offset during pop-up, andcontrols the playback type of the video or PG_text subtitle stream whenthe pop-up menu is set to “on” in the IG stream. The“Fixed_offset_during_Popup” field is set to “on” when the“user_interface_model” field in the IG stream is on, namely, when theuser interface of the pop-up menu is set to “on”. Also, the“Fixed_offset_during_Popup” field is set to “off” when the“user_interface_model” field in the IG stream is off, namely, when the“AlwaysON” user interface is set.

When the fixed offset during pop-up is set to “0”, namely, when thepop-up menu is set to “off” in the user interface of the IG stream, thevideo stream is in the B-D presentation mode, the stereoscopic PG streambecomes the stereoscopic playback type, and during playback in the 1plane+offset mode, the PG text subtitle stream is in the 1 plane+offsetmode.

When the fixed offset during pop-up is set to “1”, namely, when thepop-up menu is set to “on” in the IG stream, the video stream is in theB-B presentation mode. The stereoscopic PG stream is in the 1plane+offset mode, and the PG stream for “1 plane+offset” is played backas the “1 plane+zero offset” playback type.

In the 1 plane+offset mode, the PG_text subtitle stream becomes “1plane+zero offset”.

FIGS. 10A through 10C show the stream registration sequences in theextension stream selection table.

FIG. 10A shows the internal structure of the dependent-view video streamregistration sequence. The dependent-view video stream registrationsequence is composed of v(x) pieces of SS_dependent_view_blocks. Here,“v(x)” represents the number of primary video streams that are permittedto be played back in the basic stream selection table of the playiteminformation #x. The lead lines in the drawing indicates the close-up ofthe internal structure of the dependent-view video stream registrationsequence. As indicated by the lead lines, the “SS_dependent_view_block”is composed of the stream number, stream entry, stream attribute, andthe number of offset sequences (number_of_offset_sequence).

The stream entry includes: a sub-path identifier reference(ref_to_Subpath_id) specifying a sub-path to which the playback path ofthe dependent-view video stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which thedependent-view video stream is stored; and a packet identifier(ref_to_stream_PID_subclip) of the dependent-view video stream in thisstream file.

The “stream attribute” includes the language attribute of thedependent-view video stream.

The “the number of offset sequences (number_of_offset_sequence)”indicates the number of offsets provided in the dependent-view videostream.

The “offset sequence number information” (“number_of_offset_sequence” inthe drawing) indicates the number of offset sequences in thedependent-view stream.

The value of the “offset sequence number information in the extensionstream selection table is identical with the number of offset sequencesthat is included in the dependent-view stream.

The dependent-view video stream registration sequences shown in FIG. 10Aindicate that a plurality of pieces of stream registration informationare provided in correspondence with a plurality of dependent-view videostreams. However, FIG. 10A merely illustrates the data structurethereof. In the actuality, since there is only one base-view videostream normally, the number of pieces of stream registration informationfor the dependent-view video stream is one.

FIG. 10B shows the internal structure of the PG stream registrationsequence. The PG stream registration sequence is composed of P(x) piecesof stream registration information. Here, “P(x)” represents the numberof PG streams that are permitted to be played back in the basic streamselection table of the playitem information #x.

The lead lines in the drawing indicates the close-up of the commoninternal structure of the PG stream registration sequences.

The “PG_text subtitle offset sequence ID reference information(PGtextST_offset_sequence_id_ref)” is PG_text subtitle stream offsetsequence reference information, and indicates an offset sequence withrespect to the PG_text subtitle stream in the 1 plane+offset mode.

The offset metadata is supplied by the access unit of the dependent-viewvideo stream. The playback device should apply the offset, which issupplied by this field, to the presentation graphics (PG) plane of the 1plane+offset mode type.

When the field is an undefined value (FF), the playback device does notapply this offset to the PG stream plane memory.

The “stereoscopic PG presence/absence flag (is_SS_PG)” indicates thevalidity and presence of the following in the PG stream: the left-eye IGstream entry; the right-eye IG stream entry; and the stream attributes.When the structure is absent in the stereoscopic PG stream, this fieldshould be set to “0”; and when the structure is present in thestereoscopic PG stream, this field should be set to “1”.

The “left-eye stream entry” includes: a sub-path identifier reference(ref_to_Subpath_id) specifying a sub-path to which the playback path ofthe left-eye PG stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which the left-eyePG stream is stored; and a packet identifier (ref_to_stream_PID_subclip)of the left-eye PG stream in this stream file.

The “right-eye stream entry” includes: a sub-path identifier reference(ref_to_Subpath_id) specifying a sub-path to which the playback path ofthe right-eye PG stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which theright-eye PG stream is stored; and a packet identifier(ref_to_stream_PID_subclip) of the right-eye PG stream in this streamfile. When the stream file referenced by the“stream_entry_for_dependent_view” in the stream registration informationin the extension stream selection table is different from the streamfile referenced by the stream entry in the basic stream selection table,a stream file storing the right-eye PG stream needs to be read again.

The “common stream attribute” includes language attributes of theleft-eye PG stream and the right-eye PG stream.

The “stereoscopic PG_text subtitle offset sequence ID referenceinformation (SS_PG_textST_offset_sequence_id_ref)” is referenceinformation for referencing an offset sequence for the PG_text subtitlestream, and indicates the offset sequence for the PG_text subtitlestream. The playback device should apply the offset, which is suppliedby this field, to the PG plane.

When the field is an undefined value (FF), the playback device does notapply this offset to the PG stream plane memory.

The “Video shift mode (video_shift_mode)” is a region-saving flag thatdefines processing of saving a display region of a subtitle. Theregion-saving flag indicates whether the display region of the subtitleis to be saved in the upper end or the lower end in the video plane.When the display region of the subtitle is neither saved in the upperend nor the lower end in the video plane, the video shift mode is set to“Keep”. When the video_shift_mode is set to “Keep”, picture data storedin the video plane memory is neither shifted upward nor downward, andthe picture data are overlaid with a subtitle stored in the PG streamplane memory, as shown in FIG. 11.

When the subtitle display region of the PG_text subtitle stream islocated in the lower end of the video plane, the video shift mode is setto “Up”. When the subtitle display region of the PG_text subtitle streamis located in the upper end of the video plane, the video shift mode isset to “Down”.

When subtitles obtained by decoding a PG stream whose video_shift_modeis set to “Up” are located in the lower end of the screen. Accordingly,as shown in FIG. 12A, picture data stored in the video plane memory isshifted upward, and the picture data is overlaid with a subtitle storedin the PG stream plane memory. This can prevent the subtitle from beingdisplayed as if the subtitle dents in stereoscopic images. Whensubtitles obtained by decoding a PG stream whose video_shift_mode is setto “Down” are located in the upper end of the screen. Accordingly, asshown in FIG. 12B, picture data stored in the video plane memory isshifted downward, and the picture data are overlaid with subtitlesstored in the PG stream plane memory. This can prevent the subtitlesfrom being displayed as if the subtitles dent in stereoscopic images.

FIG. 10C shows the internal structure of the IG stream registrationsequence. The IG stream registration sequence is composed of I(x) piecesof stream registration information. Here, “I(x)” represents the numberof IG streams that are permitted to be played back in the basic streamselection table of the playitem information #x. The lead lines in thedrawing indicate the close-up of the common internal structure of the PGstream registration sequences.

The “IG offset sequence ID reference information(IG_offset_sequence_id_ref)” is an interactive graphics offset sequencereference, and is a reference to the sequence ID of the IG stream in the1 plane+offset mode. This value indicates an offset sequence ID definedfor the offset sequence. As described above, the offset metadata issupplied by the dependent-view video stream. The playback device shouldapply the offset, which is supplied by this field, to the IG stream ofthe 1 plane+offset mode type.

When the field is an undefined value (FF), the playback device does notapply this offset to the interactive graphics (IG) stream plane.

The “B-B mode offset direction information(IG_Plane_offset_direction_during_BB_video)” is the user interface ofthe pop-up menu in the B-B presentation mode, and indicates the offsetdirection in the IG plane in the 1 plane+offset mode while the IG streamis played back.

When this field is set to “0”, it is the front setting. That is to say,the plane memory exists between the television and the viewer, and theplane is shifted rightward during the left-view period, and the plane isshifted leftward during the right-view period.

When this field is set to a value “1”, it is the behind setting. That isto say, the plane memory exists behind the television or the screen, andthe left plane is shifted rightward, and the right plane is shiftedleftward.

The “B-B mode offset value information(IG_Plane_offset_value_during_BB_video)” indicates, in units of pixels,the offset value of the IG plane in the 1 plane+offset mode while the IGstream is played back by the user interface of the pop-up menu in theB-B presentation mode.

The “stereoscopic IG presence/absence flag (is_SS_IG)” indicates thevalidity and presence of the following in the IG stream: the left-eye IGstream entry; the right-eye IG stream entry; and the stream attributes.When the structure is absent in the stereoscopic PG stream, this fieldshould be set to “0”. When the structure is present in the stereoscopicPG stream, this field should be set to “1”.

The “left-eye stream entry” includes: a sub-path identifier reference(ref_to_Subpath_id) specifying a sub-path to which the playback path ofthe left-eye IG stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which the left-eyeIG stream is stored; and a packet identifier (ref_to_stream_PID_subclip)of the left-eye IG stream in this stream file.

The “right-eye stream entry” includes: a sub-path identifier reference(ref_to_Subpath_id) specifying a sub-path to which the playback path ofthe right-eye IG stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which theright-eye IG stream is stored; and a packet identifier(ref_to_stream_PID_subclip) of the right-eye IG stream in this streamfile. When the stream file referenced by the“stream_entry_for_dependent_view” in the stream registration informationin the extension stream selection table is different from the streamfile referenced by the stream entry in the basic stream selection table,a stream file storing the right-eye IG stream needs to be read.

The “common stream attribute” includes language attributes of theleft-eye IG stream and the right-eye IG stream.

The “stereoscopic IG offset sequence ID reference information” is areference to the offset sequence ID for the stereoscopic-type IG stream,and indicates the offset sequence for the offset metadata of thedependent-view video stream. The playback device should apply theoffset, which is supplied by this field, to the stereoscopic-type IGplane.

When the field is an undefined value (FF), the playback device does notapply this offset to the IG plane.

The PG_text subtitle stream offset sequence reference information andthe IG stream offset sequence reference information are written in thestream registration information in correspondence with stream numbers.Therefore, when the stream selection procedure is executed due to achange of the device state or occurrence of a request for stream changeand a stream number corresponding to the language setting on the deviceside is set in the stream number register, an offset sequence indicatedby a reference corresponding to the new stream number is supplied fromthe video decoder to the shift unit. With this structure, an optimumoffset sequence corresponding to the language setting in the playbackdevice is supplied to the shift unit, thus it is possible to set thedepth of the graphics in 1 plane+offset mode to an optimum valuecorresponding to the language setting in the playback device.

The following describes restrictions for the extension stream selectiontable.

The stream entry in the stereoscopic dependent-view block should notchange in the playlist.

When the type of the stream entry in the stereoscopic dependent-viewblock is the ES type (stream type=2) that is used by the sub-path, thesub-path ID reference and the subclip entry ID reference(ref_to_subclip_entry_id) do not change in the playlist.

Only two types of elementary streams are permitted to be the types ofthe stream entry, stream entry for the base view, and stream entry forthe dependent view. The two types are: ES (stream type=1) in the AV clipused by the playitem; and ES (stream type=2) in the AV clip used by thesub-path.

In the stereoscopic dependent-view block, the stream encoding method inthe stream attribute is set to “0x20”.

FIG. 14 shows what elementary streams are demultiplexed from the main TSand the sub-TSs with use of the basic stream selection table and theextension stream selection table.

The middle part of FIG. 14 shows the demultiplexing unit. The upper partof FIG. 14 shows the combination of the basic stream selection table andthe extension stream selection table. The left side of FIG. 14 shows themain TS and the sub-TSs, and the right side of FIG. 14 shows thedemultiplexed base-view video stream, dependent-view video stream,left-eye PG stream, right-eye PG stream, left-eye IG stream, right-eyeIG stream, and primary audio stream.

FIG. 15 shows stream numbers to be assigned in the 2D output mode andthe 3D output mode.

The vertical column on the left side of FIG. 15 shows the followingstream numbers: primary video stream #1; primary audio streams #1 and#2; PG_text subtitle streams #1, #2 and #3; and IG streams #1 and #2.

The element streams arranged on the left side of FIG. 15, enclosed by adotted line, are element streams that are targeted for demultiplexingonly in the 2D output mode, and that are permitted by the streamselection table (STN_table) to be played back.

The element streams arranged on the right side of FIG. 15, enclosed by adotted line, are element streams that are targeted for demultiplexingonly in the 3D output mode, and that are permitted by the extensionstream selection table (STN_table_SS) to be played back.

The element streams enclosed by the combined dotted lines of the leftside and the right side are element streams that are targeted fordemultiplexing in the 3D output modes.

With regard to the video stream #1, the MPEG4-MVC base-view video streamis enclosed by the combined dotted lines of the left side and the rightside. This indicates that the MPEG4-MVC base-view video stream istargeted to be played back in both the 2D and the 3D output modes. Onthe other hand, the MPEG4-MVC dependent-view video stream is enclosed byonly the dotted line of the right side. This indicates that theMPEG4-MVC dependent-view video stream is to be played back only in the3D output mode.

With regard to the primary audio streams #1 and #2, they are bothenclosed by the combined dotted lines of the left side and the rightside. This indicates that the audio streams #1 and #2 are targeted to beplayed back in both the 2D and the 3D output modes.

With regard to the PG_text subtitle streams, the PG_text subtitlestreams #1 and #2 are 2D PG streams, and are enclosed by the combineddotted lines of the left side and the right side, indicating that theyare targeted to be played back in both the 2D and the 3D output modes.On the other hand, the left-eye PG stream and the right-eye PG streamare enclosed by only the dotted line of the right side. This indicatesthat the left-eye PG stream and the right-eye PG stream are to be playedback only in the 3D output mode.

With regard to the IG streams, the IG streams #1 and #2 are 2D IGstreams, and are enclosed by the combined dotted lines of the left sideand the right side. This indicates that IG streams #1 and #2 aretargeted to be played back only in the 2D output mode. On the otherhand, the left-eye IG stream and the right-eye IG stream are enclosed byonly the dotted line of the right side. This indicates that the left-eyeIG stream and the right-eye IG stream are to be played back in the 2Doutput mode and the 3D output mode.

As understood from the above description, in the 3D output mode, thedependent-view video stream is added to the target for playbackregarding the stream type “video stream”.

It is also understood that, in the 3D output mode, the left-eye PGstream and the right-eye PG stream are added to the target for playbackregarding the stream type “PG stream”, and the left-eye IG stream andthe right-eye IG stream are added to the target for playback regardingthe stream type “IG stream”. The reason for adding the left-eye PGstream and the right-eye PG stream to the target for playback is thatthe left-eye PG stream and the right-eye PG stream are used to realizethe stereoscopic playback in the 3D output mode. The reason for addingthe left-eye IG stream and the right-eye IG stream to the target forplayback is that the left-eye IG stream and the right-eye IG stream areused to realize the stereoscopic playback in the 3D output mode.

This completes the description of the recording medium. In thefollowing, the playback device will be described in detail.

FIG. 16 shows the internal structure of the playback device. As shown inFIG. 16, the playback device includes a reading unit 201, a memory 202,a register set 203, a decoder 204, a demultiplexing unit 205, a planememory set 206, a shift unit 207, a layer overlay unit 208, atransmission/reception unit 209, and a playback control unit 210. Theinternal structure of FIG. 16 is composed of the minimum structuralelements that are required to realize the playback device provided witha problem solving means. A more detailed internal structure will bedescribed in a later embodiment.

The reading unit 201 reads out, from the recording medium, the indextable, program file, playlist information file, stream information file,and stream file. When reading the stereoscopic interleaved stream file,the reading unit 201 performs a process in which it divides thestereoscopic interleaved stream file into (i) an ATC sequence 1corresponding to the main TS and (ii) an ATC sequence 2 corresponding tothe sub-TS, by using (a) the extent start point information of the clipbase information in the 3D clip information file and (b) the extentstart point information in the clip dependent information, and storesthe ATC sequences 1 and 2 into different read buffers. This division isrealized by repeating two processes: the first process of extracting,from the stereoscopic interleaved stream file, as many source packets asthe number of packets corresponding to the source packet numberindicated by the extent start point information in the clip dependentinformation, and adding the extracted source packets into the ATCsequence 1; and the second process of extracting, from the stereoscopicinterleaved stream file, as many source packets as the number of packetscorresponding to the source packet number indicated by the extent startpoint information in the clip base information, and adding the extractedsource packets into the ATC sequence 2.

The memory 202 stores a combined stream registration sequence that isobtained by combining the extension stream selection table and the basicstream selection table included in the playlist information.

The player number register 203 includes a plurality of registers thatare required for the playback device to operate.

The decoder 204 is composed of a video decoder 211, a PG decoder 212, anIG decoder 214, and an audio decoder which correspond to respectivestream types.

The demultiplexing unit 205 is provided with: a source depacketizer forconverting the source packets into TS packets; and a PID filter forperforming the packet filtering. The demultiplexing unit 205 convertssource packets having packet identifiers written in stream entries ofthe basic stream selection table in the 3D playlist information into TSpackets, and outputs the TS packets to the decoder. Also, thedemultiplexing unit 207 converts source packets having packetidentifiers written in stream entries of the stereoscopic streamselection table in the 3D playlist information into TS packets, andoutputs the TS packets to the decoder. Which packet identifiers, among aplurality of packet identifiers written in a plurality of stream entriesof the basic and stereoscopic stream selection tables, are to be used isdetermined in accordance with the setting in the stream number registeramong the player status registers. The stream number register is aregister for storing the current stream number.

The plane memory set 206 is composed of a plurality of plane memories.

These plane memories constitute a layer model, and the data stored ineach plane memory are used to overlay the layers with each other. Theplane memory set includes a left-eye plane memory and a right-eye planememory. Respective non-compressed picture data obtained by decoding thebase-view and dependent-view components of each access unit are writteninto the left-eye and right-eye plane memories. The plane memory setincludes a left-eye plane memory and a right-eye plane memory.Respective non-compressed picture data obtained by decoding thebase-view and dependent-view components of each access unit are writteninto the left-eye and right-eye plane memories. The writing is performedeach time the playback start time indicated by the presentation timestamp of each access unit is reached.

To which of the left-eye plane memory and the right-eye plane memory thepicture data after decoding is to be written is determined in accordancewith the base-view indicator in the playlist information. When thebase-view indicator specifies the base-view video stream as “for theleft eye”, the picture data of the base-view video stream is written tothe left-eye plane memory, and the picture data of the dependent-viewvideo stream is written to the right-eye plane memory.

When the base-view indicator specifies the base-view video stream as“for the right eye”, the picture data of the base-view video stream iswritten to the right-eye plane memory, and the picture data of thedependent-view video stream is written to the left-eye plane memory.These view components are output to the display device in sequence. Morespecifically, in one frame period, the picture data stored in theleft-eye plane memory and the picture data stored in the right-eye planememory are output simultaneously.

The shift unit 207 shifts the pixel coordinates.

The layer overlay unit 208 overlays the layers in the plurality of planememories.

The transmission/reception unit 209 transits to a data transfer phasevia a mutual authentication phase and a negotiation phase, when playbackdevice is connected with another device in the home theater system viaan interface. The transmission/reception unit 209 performs data transferin the transfer phase.

In the negotiation phase, the capabilities of the partner device(including the decode capability, playback capability, and displayfrequency) are grasped, and the capabilities are set in the playersetting register, so that the transfer method for the succeeding datatransfers is determined. The negotiation phase includes a mutualauthentication phase in which each of the devices confirms theauthenticity of the other device. After the negotiation phase, one lineof the pixel data in the non-compression/plaintext format in the picturedata after the layer overlaying is transferred to the display device ata high transfer rate in accordance with the horizontal sync period ofthe display device. On the other hand, in the horizontal and verticalblanking intervals, audio data in the non-compression/plaintext formatis transferred to other devices (including an amplifier and a speaker aswell as the display device) connected with the playback device. Withthis structure, the devices such as the display device, amplifier andspeaker can receive the picture data and audio data both in thenon-compression/plaintext format, and a reproduced output is achieved.Further, when the partner device has the decode capability, apass-through transfer of the video and audio streams is possible. In thepass-through transfer, it is possible to transfer the video stream andaudio stream in the compressed/encrypted format, as they are.

The playback control unit 210 executes a random access from an arbitrarytime point on the time axis of the video stream. More specifically, whenit is instructed to play back from an arbitrary time point on the timeaxis of the video stream, the playback control unit 210 searches for asource packet number of an access unit corresponding to the arbitrarytime point, by using a base entry map in the 3D stream information fileand an extension entry map. The access unit includes a pair of a viewcomponent of the base-view video stream and a view component of thedependent-view video stream, and this searching identifies a sourcepacket number of a source packet storing an access unit delimiter forthe access unit. Reading from the source packet number and decodingenable a random access to be performed. When a 3D playlist is to beplayed back, random accesses to the main TS and the sub-TS are executedby using the in-time and the out-time defined in the main-pathinformation and the in-time and the out-time defined in the sub-pathinformation of the 3D playlist information, to start the playback of theplaylist.

The video decoder 211 is a representative decoder among the decodersconstituting the decoder set 204. The video decoder 211 preloads viewcomponents that constitute the dependent-view video stream, and decodesview components of a picture type for which the Instantaneous DecoderRefresh (IDR) at the start of the closed GOP in the base-view videostream is intended (IDR type). In this decoding, all the coded databuffers and decode data buffers are cleared. After decoding the viewcomponents of the IDR type in this way, (i) view components followingthe base-view video stream compress-encoded based on the correlationwith these view components and (ii) view components of thedependent-view video stream, are decoded. Non-compressed picture data isobtained by this decoding of the view components. The obtainednon-compressed picture data is stored in the decode data buffer to beused as the reference picture.

By using the reference picture, the motion compensation is performedonto (i) view components following the base-view video stream and (ii)view components of the dependent-view video stream. Non-compressedpicture data with regard to (i) view components following the base-viewvideo stream and non-compressed picture data with regard to (ii) viewcomponents of the dependent-view video stream are obtained by the motioncompensation. The obtained non-compressed picture data are stored in thedecode data buffer to be used as reference pictures. The above-describeddecoding is performed each time the decode start time indicated in thedecode time stamp of each access unit is reached.

The following describes the PG decoder 212, text subtitle decoder 213,and IG decoder 214, and the internal structures of the streams that areto be decoded by these decoders.

For the PG stream: the decoder structure is “1 decoder+1 plane” when the“1 plane+offset” method is adopted; and the decoder structure is “2decoders+2 planes” when the 3D-LR method is adopted.

Similarly, for the IG stream: the decoder structure is “1 decoder+1plane” when the “1 plane+offset” method is adopted; and the decoderstructure is “2 decoders+2 planes” when the 3D-LR method is adopted.

For the text subtitle stream for which the 3D-LR method cannot beadopted: the decoder structure is “1 decoder+1 plane” when the “1plane+offset” method is adopted.

First, the internal structure of the PG stream, and the internalstructure of the PG decoder for decoding the PG stream will bedescribed.

Each of the left-eye PG stream and the right-eye PG stream includes aplurality of display sets. The display set is a set of functionalsegments that constitute one screen display. The functional segments areprocessing units that are supplied to the decoder while they are storedin the payloads of the PES packets which each have the size ofapproximately 2 KB, and are subjected to the playback control with useof the DTSs and PTSs.

The display set falls into the following types.

A. Epoch-start Display Set

The epoch-start display set is a set of functional segments that startthe memory management by resetting the composition buffer, code databuffer, and graphics plane in the graphics decoder. The epoch-startdisplay set includes all functional segments required for composition ofthe screen.

B. Normal-case Display Set

The normal-case display set is a display set that performs thecomposition of the screen while continuing the memory management of thecomposition buffer, code data buffer, and graphics plane in the graphicsdecoder. The normal-case display set includes functional segments thatare differentials from the preceding display set.

C. Acquisition-point Display Set

The acquisition-point display set is a display set that includes allfunctional segments required for composition of the screen, but does notreset the memory management of the composition buffer, code data buffer,and graphics plane in the graphics decoder. The acquisition-pointdisplay set may include functional segments that are different fromthose in the previous display set.

D. Epoch-continue Display Set

The epoch-continue display set is a display set that continues thememory management of the composition buffer, code data buffer, andgraphics plane in the playback device as it is when the connectionbetween a playitem permitting the playback of the PG stream and aplayitem immediately before the playitem is the “seamless connection”(CC=5) that evolves a clean break. In this case, the graphics objectsobtained in the object buffer and the graphics plane are kept to bepresent in the object buffer and the graphics plane, without beingdiscarded.

Certain time points on the playback time axis of the STC sequence areassigned to the start point and end point of these display sets, and thesame times are assigned to the left-eye view and to the right-eye view.Also, for the left-eye PG stream and the right-eye PG stream, the typesof the display sets that are present on the same time point on the timeaxis are the same. That is to say, when the display set on the left-eyeside is the epoch-start display set, the display set on the right-eyeside that is at the same time point on the time axis of the STC sequenceis the epoch-start display set.

Further, when the display set on the left-eye side is theacquisition-point display set, the display set on the right-eye sidethat is at the same time point on the time axis of the STC sequence isthe acquisition-point display set.

Each display set includes a plurality of functional segments. Theplurality of functional segments include the following.

(1) Object Definition Segment

The object definition segment is a functional segment for defining thegraphics object. The graphics definition segment defines the graphicsobject by using a code value and a run length of the code value.

(2) Pallet Definition Segment

The pallet definition segment includes pallet data that indicatescorrespondence among each code value, brightness, and red colordifference/blue color difference. The same correspondence among the codevalue, brightness, and color difference is set in both the palletdefinition segment of the left-eye graphics stream and the palletdefinition segment of the right-eye graphics stream.

(3) Window Definition Segment

The window definition segment is a functional segment for defining arectangular frame called “window” in the plane memory that is used toextend the non-compressed graphics object onto the screen. The drawingof the graphics object is restricted to the inside of the plane memory,and the drawing of the graphics object is not performed outside thewindow.

Since a part of the plane memory is specified as the window fordisplaying the graphics, the playback device does not need to performthe drawing of the graphics for the entire plane. That is to say, theplayback device only needs to perform the graphics drawing onto thewindow that has a limited size. The drawing of the part of the plane fordisplay other than the window can be omitted. This reduces the load ofthe software on the playback device side.

(4) Screen Composition Segment

The screen composition segment is a functional segment for defining thescreen composition using the graphics object, and includes a pluralityof control items for the composition controller in the graphics decoder.The screen composition segment is a functional segment that defines indetail the display set of the graphics stream, and defines the screencomposition using the graphics object. The screen composition falls intothe types such as Cut-In/-Out, Fade-In/-Out, Color Change, Scroll, andWipe-In/-Out. With use of the screen composition defined by the screencomposition segment, it is possible to realize display effects such asdeleting a subtitle gradually, while displaying the next subtitle.

(5) End Segment

The end segment is a functional segment that is located at the end of aplurality of functional segments belonging to one display set. Theplayback device recognizes a series of segments from the screencomposition segment to the end segment as the functional segments thatconstitute one display set.

In the PG stream, the start time point of the display set is identifiedby the DTS of the PES packet storing the screen composition segment, andthe end time point of the display set is identified by the PTS of thePES packet storing the screen composition segment.

The left-eye graphics stream and the right-eye graphics stream arepacketized elementary streams (PES). The screen composition segment isstored in the PES packet. The PTS of the PES packet storing the screencomposition segment indicates the time when the display by the displayset to which the screen composition segment belongs should be executed.

The value of the PTS of the PES packet storing the screen compositionsegment is the same for both the left-eye video stream and the right-eyevideo stream.

(Decoder Models of PG Decoder)

The PG decoder includes: a “coded data buffer” for storing functionalsegments read from the PG stream; a “stream graphics processor” forobtaining a graphics object by decoding the screen composition segment;an “object buffer” for storing the graphics object obtained by thedecoding; a “composition buffer” for storing the screen compositionsegment; and a “composition controller” for decoding the screencomposition segment stored in the composition buffer, and performing ascreen composition on the graphics plane by using the graphics objectstored in the object buffer, based on the control items included in thescreen composition segment.

A “transport buffer” for adjusting the input speed of the TS packetsconstituting the functional segments is provided at a location beforethe graphics plane.

Also, at locations subsequent to the graphics decoder, a “graphicsplane”, a “CLUT unit” for converting the pixel codes constituting thegraphics object stored in the graphics plane into values ofbrightness/color difference based on the pallet definition segment, anda “shift unit” for the plane shift are provided.

The pipeline in the PG stream makes it possible to simultaneouslyexecutes the following processes: the process in which the graphicsdecoder decodes an object definition segment belonging to a certaindisplay set and writes the graphics object into the graphics buffer; andthe process in which a graphics object obtained by decoding an objectdefinition segment belonging to a preceding display set is written fromthe object buffer to the plane memory.

FIGS. 17A and 17B show the internal structure of the PG decoder. FIG.17A shows a decoder model for displaying data in the 1 plane+offsetmode. FIG. 17B shows a decoder model for displaying data in the LR mode.

In FIGS. 17A and 17B, the PG decoder itself is represented by a framedrawn by the solid line, and a portion that follows the graphics decoderis represented by a frame drawn by the chain line.

FIG. 17A shows that the PG decoder has “1 decoder” structure, and thegraphics plane has “1 plane” structure. However, the output of thegraphics plane branches to the left-eye output and the right-eye output.Thus the left-eye output and the right-eye output are each provided witha shift unit.

FIG. 17B shows that two series of “transport buffer”-“PGdecoder”-“graphics plane”-“CLUT unit” are provided so that the left-eyestream and the right-eye stream can be processed independently.

The offset sequence is contained in the right-eye video stream. Thus, inthe plane offset format, the PG decoder has “1 decoder” structure, andthe output from the PG decoder is supplied to the left-eye view and theright-eye view by switching therebetween.

The PG decoder performs the following to switch between 2D and 3D.

1. The mutual switching between the 1 plane+offset mode and the 2D modeis performed seamlessly. This is realized by invalidating the “Offset”.

2. When switching between the 3D-LR mode and the 2D mode is performed,the display of the subtitle temporarily disappears because the switchingbetween the modes requires switching between PIDs. This is the same asthe switching between streams.

This completes the explanation of the PG decoder. In the following, thetext subtitle decoder will be described in detail.

(Decoder Models of Text Subtitle Decoder)

The text subtitle decoder is composed of a plurality of pieces ofsubtitle description data.

The text subtitle decoder includes: a “subtitle processor” forseparating the text code and the control information from the subtitledescription data; a “management information buffer” for storing the textcode separated from the subtitle description data; a “text render” forextending the text code in the management information buffer to the bitmap by using the font data; an “object buffer” for storing the bit mapobtained by the extension; and a “drawing control unit” for controllingthe text subtitle playback along the time axis by using the controlinformation separated from the subtitle description data.

The text subtitle decoder is preceded by: a “font preload buffer” forpreloading the font data; a “TS buffer” for adjusting the input speed ofthe TS packets constituting the text subtitle stream; and a “subtitlepreload buffer” for preloading the text subtitle stream before theplayback of the playitem.

The graphics decoder is followed by a “graphics plane”; a “CLUT unit”for converting the pixel codes constituting the graphics object storedin the graphics plane into values of brightness and color differencebased on the pallet definition segment; and a “shift unit” for the planeshift.

FIGS. 18A and 18B show the internal structure of the text subtitledecoder. FIG. 18A shows a decoder model of the text subtitle decoder inthe 1 plane+offset mode. FIG. 18B shows a decoder model of the textsubtitle decoder in the 3D-LR method. In FIGS. 18A and 18B, the textsubtitle decoder itself is represented by a frame drawn by the solidline, a portion that follows the text subtitle decoder is represented bya frame drawn by the chain line, and a portion that precedes the textsubtitle decoder is represented by a frame drawn by the dotted line.

FIG. 18A shows that the output of the graphics plane branches to theleft-eye output and the right-eye output, and that the left-eye outputand the right-eye output are each provided with a shift unit.

FIG. 18B shows that the left-eye graphics plane and the right-eyegraphics plane are provided, and that the bit map extended by the textsubtitle decoder is written into the graphics planes.

The text subtitle stream differs from the PG stream as follows. That isto say, the font data and the character code are sent, not the graphicsdata is sent as the bit map, so that the rendering engine generates thesubtitle. Thus the stereoscopic viewing of the subtitle is realized inthe 1 plane+offset mode.

This completes the description of the text subtitle stream and the textsubtitle decoder. Next, the internal structure of the IG stream and thestructure of the IG decoder will be described.

(IG stream)

Each of the left-eye IG stream and the right-eye IG stream includes aplurality of display sets. Each display set includes a plurality offunctional segments. As is the case with the PG stream, the display setfalls into the following types. epoch-start display set, normal-casedisplay set, acquisition-point display set, and epoch-continue displayset.

The plurality of functional segments belonging to these display setsinclude the following types.

(1) Object Definition Segment

The object definition segment of the IG stream is the same as that ofthe PG stream. However, the graphics object of the IG stream defines thein-effect and out-effect of pages, the normal, selected, and activestates of the button members. The object definition segments are groupedinto those that define the same state of the button members, and thosethat constitute the same effect image. The group of object definitionsegments defining the same state is called a “graphics data set”.

(2) Pallet Definition Segment

The pallet definition segment of the IG stream is the same as that ofthe PG stream.

(3) Interactive Control Segment

The interactive control segment includes a plurality of pieces of pageinformation. The page information is information that defines a screencomposition of the multi-page menu. Each piece of page informationincludes an effect sequence, a plurality of pieces of buttoninformation, and a reference value of a pallet identifier.

The button information is information that realizes an interactivescreen composition on each page constituting the multi-page menu bydisplaying the graphics object as one state of a button member.

The effect sequence constitutes the in-effect or the out-effect with useof the graphics object, and includes effect information, where thein-effect is played back before a page corresponding to the pageinformation is displayed, and the out-effect is played back after thepage is displayed.

The effect information is information that defines each screencomposition for playing back the in-effect or the out-effect. The effectinformation includes: a screen composition object that defines a screencomposition to be executed in the window (partial region) defined by thewindow definition segment on the graphics plane; and effect periodinformation that indicates a time interval between the current screenand the next screen in the same region.

The screen composition object in the effect sequence defines a controlthat is similar to the control defined by the screen composition segmentof the PG stream. Among the plurality of object definition segments, anobject definition segment that defines the graphics object used for thein-effect is disposed at a location that precedes an object definitionsegment that defines the graphics object used for the button member.

Each piece of button information in the page information is informationthat an interactive screen composition on each page constituting themulti-page menu by displaying the graphics object as one state of abutton member. The button information includes a set button page commandthat, when a corresponding button member becomes active, causes theplayback device to perform the process of setting a page other than thefirst page as the current page.

To make it possible for the offset in the plane shift to be changed foreach page during playback of the IG stream, a navigation command forchanging the offset is incorporated into the button information, and the“auto-activate” of the navigation command is defined in thecorresponding piece of button information, in advance. This makes itpossible to change automatically the value or direction of the offsetdefined in the stream registration information of the IG stream.

(4) End Segment

The end segment is a functional segment that is located at the end of aplurality of functional segments belonging to one display set. A seriesof segments from the interactive control segment to the end segment arerecognized as the functional segments that constitute one display set.

The following are the control items of the interactive control segmentthat are the same for both the left-eye graphics stream and theright-eye graphics stream: button adjacency information; selectiontime-out time stamp; user time-out duration; and composition time-outinformation.

1. Button Adjacency Information

The button adjacency information is information that specifies a buttonto be changed to the selected state when a key operation specifying anyof upward, downward, leftward, and rightward is performed while acertain button adjacent to the specified button is in the selectedstate.

2. Selection Time-out Time Stamp

The selection time-out time stamp indicates a time-out time that isrequired to automatically activate a button member in the current pageand cause the playback device to execute the button member.

3. User Time-out Duration

The user time-out duration indicates a time-out time that is required toreturn the current page to the first page so that only the first page isdisplayed.

4. Composition Time-out Information

The composition time-out information indicates a time period that isrequired to end an interactive screen display by the interactive controlsegment. With respect to the IG stream, the start time point of adisplay set is identified by the DTS of the PES packet storing theinteractive control segment, and the end time point of the display setis identified by the composition time-out time of the interactivecontrol segment. The same DTS and the same composition time-out time areset for both the left eye and the right eye.

(Decoder Models of IG Decoder)

The IG decoder includes: a “coded data buffer” for storing functionalsegments read from the IG stream; a “stream graphics processor” forobtaining a graphics object by decoding the screen composition segment;an “object buffer” for storing the graphics object obtained by thedecoding; a “composition buffer” for storing the screen compositionsegment; and a “composition controller” for decoding the screencomposition segment stored in the composition buffer, and performing ascreen composition on the graphics plane by using the graphics objectstored in the object buffer, based on the control items included in thescreen composition segment.

A “transport buffer” for adjusting the input speed of the TS packetsconstituting the functional segments is provided at a location beforethe graphics plane.

Also, at locations after the graphics decoder, a “graphics plane”, a“CLUT unit” for converting the pixel codes constituting the graphicsobject stored in the graphics plane into values of brightness/colordifference based on the pallet definition segment, and a “shift unit”for the plane shift are provided.

FIGS. 19A and 19B show decoder models of the IG decoder. In FIGS. 19Aand 19B, the IG decoder itself is represented by a frame drawn by thesolid line, a portion that follows the graphics decoder is representedby a frame drawn by the chain line, and a portion that precedes the IGdecoder is represented by a frame drawn by the dotted line. FIG. 19Ashows a decoder model for displaying the 2D-format IG stream in the LRformat in the 1 plane+offset mode. FIG. 19B shows a decoder model of theIG stream for displaying LR-format data.

These decoders include a circuit for reflecting values of systemparameters onto the offsets so that the program can control the depthinformation of the menu graphics.

FIG. 19B shows a two-decoder model that enables the offset values to bechanged with use of a command. Accordingly, in this decoder model, thedepth information of the menu can be changed by the command. Note thatdifferent offset values may be set for the left view and the right view.On the other hand, in the depth method, the offset is invalid.

The composition controller in the graphics decoder realizes the initialdisplay of the interactive screen by displaying the current button,among a plurality of button members in the interactive screen, by usingthe graphics data of the graphics data set corresponding to the selectedstate, and displaying the remaining buttons by using the graphics dataset corresponding to the normal state.

When a user operation specifying any of upward, downward, leftward, andrightward is performed, it writes, into the button number register, anumber of a button member that is present in the direction specified bythe user operation among a plurality of button members in the normalstate and adjacent to the current button, the writing causing the buttonmember having become newly the current button to change from the normalstate to the selected state.

In the interactive screen, when a user operation for changing the buttonmember from the selected state to the active state is performed, theinteractive screen is updated by extracting the graphics dataconstituting the active state from the graphics data set and displayingthe extracted graphics data.

The update of the interactive screen should be executed in common to theleft-eye view and the right-eye view. Thus it is preferable that theleft-eye graphics decoder and the right-eye graphics decoder have incommon a composition controller for the two-decoder model.

In the above-described case, the inter-changing is realized by using thesame navigation command for both the left-eye view and the right-eyeview of the stereoscopic IG stream, and setting the same buttonstructure for both the 3D graphics object and the 2D graphics object.

When switching between the 2D IG stream and the stereoscopic IG stream,it is possible to change only the displayed graphics object when theattribute and number and the like of the navigation command and buttoninformation are the same for both. Switching from the 3D-LR mode to thedisplay of only the L image can be made without reloading, but there isa possibility that the display position may be shifted. It is preferablethat the playback device performs the switching based on a flag set toindicate which is adopted by the title producer.

The following are notes on switching between modes.

-   -   Reloading does not occur when switching between the 1        plane+offset mode and the 2D mode is performed. This is because        the IG stream does not need to be reloaded, and only        invalidation of the offset is required.    -   Reloading occurs when switching between the 3D-LR mode and the        2D mode is performed. This is because the streams are different.

This completes the description of the IG stream and the IG decoder.Next, the plane memory will be described in detail.

The following describes the plane memory structure in the 1 plane+offsetmode.

The layer overlaying in the plane memory is achieved by executing asuperimposing process onto all combinations of the layers in the layermodel. In the superimposing process, pixel values of pixel data storedin the plane memories of the two layers are superimposed. The layeroverlaying by the layer overlay unit 208 is achieved by executing asuperimposing process onto all combinations of two layers among thelayers in the layer model. In the superimposing process, pixel values ofpixel data stored in the plane memories of the two layers aresuperimposed in the layer model of the plane memory.

The superimposing between layers is performed as follows. Atransmittance α as a weight is multiplied by a pixel value in unit of aline in the plane memory of a certain layer, and a weight of(1−transmittance α) is multiplied by a pixel value in unit of a line inthe plane memory of a layer below the certain layer. The pixel valueswith these brightness weights are added together. The resultant pixelvalue is set as a pixel value in unit of a line in the layer. The layeroverlaying is realized by repeating this superimposing between layersfor each pair of corresponding pixels in a unit of a line in adjacentlayers in the layer model.

A multiplication unit for multiplying each pixel value by thetransmittance to realize the layer overlaying and an addition unit foradding up the pixelsare provided at locations subsequent to the planememory, as well as the above-described CLUT unit, shift unit and thelike.

FIG. 20 shows a circuit structure for overlaying the outputs of thedecoder models and outputting the result in the 3D-LR mode. In FIG. 20,the layer models each composed of video plane, PG plane, and IG planeare enclosed by solid lines, and portions that follow the plane memoriesare enclosed by chain lines. As shown in FIG. 20, there are twoabove-described layer models. Also, there are two portions following theplane memories.

With the plane memory structure for the 3D-LR method which is providedwith two pairs of a layer model and a portion following the planememory, two pairs of the video plane, PG plane, and IG plane areprovided for the left-eye view and the right-eye view, and the outputsfrom each plane memory are overlaid, as the layer overlaying, separatelyfor the left-eye view and the right-eye view.

FIG. 21 shows a circuit structure for overlaying the outputs of thedecoder models and outputting the result in the 1 plane+offset mode.

In FIG. 21, the layer model composed of the left-eye and right-eye videoplanes, PG plane, and IG plane is encircled by the solid line, and aportion that follows the plane memory is encircled by the chain line. Asshown in FIG. 21, there is only one above-described layer model. Also,there are two portions following the plane memory.

In the 1 plane+offset mode: the video plane is provided, one for each ofthe left-eye view and right-eye view; and each of the PG plane and theIG plane is provided, one for both the left view and the right view. APG plane and an IG plane each are not separately prepared for each ofthe left-eye view and the right-eye view. There is only one plane memoryfor both the left-eye view and the right-eye view. With this structure,the above-described layer overlaying is performed onto the left-eye andright-eye outputs.

FIG. 22 shows the circuit structure for overlaying data output from thedecoder model and outputting the overlaid data in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode.

In the upper end 2D subtitle playback mode method and the lower end 2Dsubtitle playback mode, a video plane is prepared for each of theleft-eye view and the right-eye view. A PG plane and an IG plane eachare not separately prepared for each of the left-eye view and theright-eye view. There is only one plane memory for both the left-eyeview and the right-eye view. In accordance with the setting of theregister (PSR32), which is described later, indicating the video shiftmode of the playback device, pixel shift of the video plane is performedupward or downward by 131 pixels for each of the left-eye view and theright-eye view. Then, layer overlaying is performed on the left-eyeoutput and the right-eye output.

The playback device needs to support all of the 3D-LR mode, the 1plane+offset mode, the upper end 2D subtitle playback mode, and thelower end 2D subtitle playback mode. Thus the hardware structure of theplayback device is basically “2 decoders+2 planes”. When the modeswitches to either of the 1 plane+offset mode, the 2D output mode, theupper end 2D subtitle playback mode, and the lower end 2D subtitleplayback mode, the playback device becomes to have the “1 decoder+1plane” structure, invalidating one of the two pairs of “1 decoder+1plane”.

It is at the discretion of the manufacturer of the playback device whichof 1-decoder structure and 2-decoder structure is adopted as the decodermodel and which of 1-plane structure and 2-planes structure is adoptedas the plane model. Of course, the playback device may be designed tohave the 2-decoder and 2-plane structure, then it may be set to be ableto play back the stereoscopic PG and IG as the top-of-the-line product,and may be set not to be able to play back the stereoscopic PG and IG asthe lower-cost product. This expands the lineup. Such a configurationhaving the capability to play back the stereoscopic PG or aconfiguration having the capability to play back the stereoscopic IGexists in the register set.

The following explains the register set.

The register set is composed of a plurality of player status registersand a plurality of player setting registers. Each of the player statusregisters and player setting registers is a 32-bit register and isassigned with a register number so that a register to be accessed isidentified by the register number.

The bit positions of the bits (32 bits) that constitute each registerare represented as “b0” through “b31”. Among these, bit “b31” representsthe highest-order bit, and bit “b0” represents the lowest-order bit.Among the 32 bits, a bit sequence from bit “bx” to bit “by” isrepresented by [bx:by].

The value of an arbitrary bit range [bx:by] in a 32-bit sequence storedin the player setting register/player status register of a certainregister number is treated as an environment variable (also called“system parameter” or “player variable”) that is a variable of anoperation system in which the program runs. The program that controlsthe playback can obtain a system parameter via the system property orthe application programming interface (API). Also, unless otherwisespecified, the program can rewrite the values of the player settingregister and the player status register. For the program based on anobject-oriented programming language to do this, the program needs tohave the authority to obtain or rewrite system parameters.

The player status register is a hardware resource for storing valuesthat are to be used as operands when the MPU of the playback deviceperforms an arithmetic operation or a bit operation. The player statusregister is also reset to initial values when an optical disc is loaded,and the validity of the stored values is checked. The values that can bestored in the player status register are the current title number,current playlist number, current playitem number, current stream number,current chapter number, and so on. The values stored in the playerstatus register are temporary values because the player status registeris reset to initial values each time an optical disc is loaded. Thevalues stored in the player status register become invalid when theoptical disc is ejected, or when the playback device is powered off.

The player setting register differs from the player status register inthat it is provided with power handling measures. With the powerhandling measures, the values stored in the player setting register aresaved into a non-volatile memory when the playback device is poweredoff, and the values are restored when the playback device is powered on.The values that can be set in the player setting register include:various configurations of the playback device that are determined by themanufacturer of the playback device when the playback device is shipped;various configurations that are set by the user in accordance with theset-up procedure; and capabilities of a partner device that are detectedthrough negotiation with the partner device when the device is connectedwith the partner device.

FIG. 23 shows the internal structures of the register set 203 and theplayback control unit.

The left side of FIG. 23 shows the internal structures of the registerset 203, and the right side shows the internal structures of theplayback control unit.

The following describes the player status registers and the playersetting registers assigned with respective register numbers.

PSR0 is a stream number register for the IG stream, and stores a currentIG stream number.

PSR2 is a stream number register for the PG stream, and stores a currentPG stream number.

PSR24 is used for the setting of “Player Capability for 3D”. Thisindicates whether or not the playback device has a capability to performthe stereoscopic playback.

On the other hand, the playback control unit includes a stream selectionprocedure for determining a unique current PG stream number and a uniquecurrent IG stream number in the current playlist, by referring to thePSR24 in the register set 203 and the stream selection table of thecurrent playlist information in the memory. The stream selectionprocedure includes “Initialization” and “Procedure when playbackcondition changed”.

FIG. 25 shows the bit assignment in PSR32. The PSR32 indicates the videoshift mode of the playback device. The value of the PSR 32 is set via anAPI of a BD program, a command, or the like. Also, video_shift_moderelating to a current PG stream selected by stream switching is acquiredfrom stream registration information included in the stream selectiontable stream, and is set.

FIG. 24 shows the bit assignment in PSR24. PSR24 indicates the 3Dcapability of the playback device. The program recorded on the recordingmedium cannot change the value of PSR24.

The bit “b0” in PSR24 represents the video display capability ofstereoscopic 1280×720 50 p. More specifically, when bit “b0” is set to“0”, it indicates that the playback device does not have the processingcapability to display the 1280×720/50 Hz progressive video; and when bit“b0” is set to “1”, it indicates that the playback device has theprocessing capability to display the 1280×720/50 Hz progressive video.

The bit “b2” in PSR24 represents the stereoscopic PG capability. Morespecifically, when bit “b2” is set to “0”, it indicates that theplayback device does not have the capability to play back thestereoscopic PG; and when bit “b2” is set to “1”, it indicates that theplayback device has the capability to play back the stereoscopic PG.

The bit “b3” in PSR24 represents the stereoscopic IG capability. Morespecifically, when bit “b3” is set to “0”, it indicates that theplayback device does not have the capability to play back thestereoscopic IG; and when bit “b3” is set to “1”, it indicates that theplayback device has the capability to play back the stereoscopic IG.

The bit “b5” in PSR24 represents the BD-J capability in the 3D outputmode. More specifically, when bit “b5” is set to “1”, it indicates thatthe playback device can process the BD-J mode in the 3D output mode; andwhen bit “b5” is set to “0”, it indicates that the playback devicecannot process the BD-J mode in the 3D output mode. The use of the bit“b5” in PSR24 is not related to the subject of the present embodiment,and thus will be described in some subsequent embodiment.

As described above, PSR24 can be set to indicate whether or not thestereoscopic playback is available for each of the IG and PG This makesit possible to provide: a configuration in which each of the IG and PGdecoders is composed of two decoders and the playback device supportsthe stereoscopic playback for both IG and PG, or a configuration inwhich each of the IG and PG decoders is composed of two decoders and theplayback device supports the stereoscopic playback for only PG and the 1plane+offset mode for IG, or a converse configuration in which each ofthe IG and PG decoders is composed of two decoders and the playbackdevice supports the stereoscopic playback for only IG and the 1plane+offset mode for PG.

Furthermore, to sell the playback device as a lower-cost product, it ispossible to provide a configuration in which although each of the IG andPG decoders is composed of two decoders, the playback device supportsmerely the 1 plane+offset mode for each of IG and PG In this way, whilehaving a common configuration in which each of the IG and PG decoders iscomposed of two decoders, the present embodiment makes it possible todetermine whether to support the stereoscopic playback for each of IGand PG separately, depending on the grade of the product. This expandslineup of products of the playback device that the manufacturer canprovide.

Also, when each of or both of the IG and PG decoders is composed of onedecoder, it clearly indicates the availability of the stereoscopicplayback. Accordingly, even if the playlist can be played back in astereoscopic mode, it is possible to prevent the playback type frombeing set to the stereoscopic PG or stereoscopic IG erroneously.

The playback control having been described up to now can be realized bycausing a computer to execute a program which is generated by writingthe processing procedure represented by the flow charts of FIGS. 26through 32 in an object-oriented compiler language.

FIG. 26 shows the playlist playback procedure. In this flow chart, thecurrent playitem number is set to “1” in step S1, and then the controlenters a loop in which the steps S2 to S6 are repeated. In this loop,the steps are performed as follows. The stream number is determined bythe “procedure when playback condition is changed” (step S2). A streamfile storing an elementary stream corresponding to the stream number isopened, and the source packet sequence is read therefrom (step S3). Itis instructed that a source packet, among those constituting the sourcepacket sequence, that corresponds to the stream number should bedemultiplexed (step S4). The decoder is instructed to play back the readsource packet for the period from the in-time to the out-time of theplayitem, and for the period from the in-time to the out-time of thesub-playitem (step S5). These steps constituting the loop are repeateduntil the current playitem number becomes the last number. When it isjudged that the current playitem number is not the last number (NO instep S6), the current playitem number is incremented, and the controlmoves to step S2.

At this timing, step S7 is performed to judge whether or not there hasbeen a stream selection request. When it is judged that there has been astream selection request, the “procedure when playback condition ischanged” is executed, with the requested stream number being regarded as“x” (step S8). When it is judged that the current playitem number is thelast number (YES in step S6), the process ends.

<Determination of Current PG Stream and Playback Type Thereof>

A current PG_text subtitle stream whose stream number is to be stored inPSR2 is selected based on the output mode (PSR22), stereoscopic PGcapability in PSR24, and “is_SS_PG”.

FIG. 27 is a flow chart showing the procedure of the “procedure whenplayback condition is changed” for the PG_text subtitle stream. Amongthe steps shown in this flow chart, the process of steps S11 to S22 iscommon to the 3D output mode and the 2D output mode, and the process ofsteps S23 to S28 is unique to the 3D output mode.

In step S11, the current PG_text subtitle stream number is obtained fromPSR2. In step S12, it is judged whether the current PG_text subtitlestream number is of PG (YES) or of text subtitle stream number (NO). Instep S13, it is checked whether or not the PG stream corresponding tothe current PG_text subtitle stream number satisfies conditions (A) and(B).

Here, the conditions (A) and (B) are defined as follows.

Condition (A): The playback device has a capability to decode a PGstream that is identified by the current PG_text subtitle stream number.

Condition (B): The playback device has a capability to play back thespecified language.

On the other hand, in step S14, it is checked whether or not the textsubtitle stream corresponding to the current PG_text subtitle streamnumber satisfies conditions (A) and (B).

Condition (A): The playback device has a capability to extend thecharacter code of the text subtitle stream, which is identified by thecurrent PG_text subtitle stream number, into a bit map. This playbackcapability is indicated in PSR30 in the PSR set 203.

Condition (B): the playback device has a capability to supportcharacteristics of the language of the text subtitle stream identifiedby the current PG_text subtitle stream number.

It should be noted here that, for a playback device to “be able todecode” a text subtitle stream which represents the subtitle of alanguage, the playback device should have the capability to extend thetext subtitle stream of the language into the bit map, and thecapability to support characteristic of the language.

Here, this will be considered by taking examples of English, Japanese,and Arabic. As for subtitle displays in English, the languagecharacteristics of English are judged to be supported only when thefunctions of “horizontal writing”, “kerning”, “double letter/logotype”are all supported.

As for subtitle displays in Japanese, the language characteristics ofJapanese are judged to be supported only when the functions of“horizontal writing” “vertical writing” “prohibit line breaks aftercertain characters”, “characters in smaller size” are all supported.

As for subtitle displays in Arabic, the language characteristics ofArabic are judged to be supported only when the functions of “renderingfrom the right to the left” and “double letter/logotype” are allsupported.

When the playback device has the capability to extend the text subtitlestream of a language into the bit map and has the capability to supportcharacteristics of the language, it can be said that the above-describedconditions (A) and (B) are satisfied. When the playback device has thecapability to extend the text subtitle stream of a language into the bitmap, but not the capability to support characteristic of the language,it can be said that the condition (B) is not satisfied, but only thecondition (A) is satisfied.

The capability to support characteristics of language is set for eachlanguage in bits constituting PSR48 through PSR61 in the register set.More specifically, PSR48 through PSR61 have flags that correspond torespective 3-byte language codes defined in ISO 639-2/T. Each of theflags is set to indicate whether or not the playback device has acapability to display a text subtitle of a language code thatcorresponds to the flag.

Among the 3-byte language codes defined in ISO 639-2/T, a 3-bytelanguage code called “ita” indicates Italian, and a 3-byte language codecalled “jpn” indicates Japanese. Also, a 3-byte language code called“jay” indicates Japanese. Approximately 430 languages are covered by the3-byte language codes defined in ISO 639-2/T. The flags in PSR48 throughPSR61 are referred to when, to determine the current PG_text subtitlestream, it is judged whether or not the text subtitle stream written inthe stream number table can be decoded. With this structure, it ispossible to perform appropriately the judgment on whether a textsubtitle stream can be decoded, even if the text subtitle stream is of aminor language.

After the above-described judgments, the control proceeds to step S15 inwhich it is judged whether or not the playback device satisfies acondition (Z).

Here, the condition (Z) is that the user is intending to play back asubtitle of an unsupported language, wherein the “unsupported language”is a language whose characteristics are not supported. The intention isindicated in PSR30 in the register set.

The control then proceeds to step S16 in which it is judged whether ornot the number of PG_text subtitle streams in the stream selection tableof the current playitem is “0”. When the stream selection tableindicates that no PG_text subtitle stream has been permitted to beplayed back, the PG_text subtitle stream number stored in PSR2 ismaintained (step S17).

When the stream selection table indicates at least one PG_text subtitlestream that is permitted to be played back, the control proceeds to stepS18 to check for the validity of the current PG_text subtitle stream. Instep S18, it is judged whether or not the current PG_text subtitlestream number is equal to or greater than the total number of streamentries in the stream selection table and conditions (A) and (B) aresatisfied.

When the result of judgment in step S18 is negative, the controlproceeds to step S20 in which it is judged whether or not the currentPG_text subtitle stream number is equal to or greater than the totalnumber of stream entries in the stream selection table and conditions(A) and (Z) are satisfied. When the result of judgment in step S20 isaffirmative, the value in PSR2 is maintained since it is determinedthat, although a PG_text subtitle stream number of a text subtitle of anunsupported language is set in PSR2, the user is intending to play backa subtitle of the unsupported language (step S21). When the result ofjudgment in step S20 is negative, an optimum stream for the currentplayitem is selected (step S22).

The steps S23 through S28 following this are unique to the 3D outputmode. Specifically, in the 3D output mode, determination processing ofupper or lower end playback type is firstly performed (step S23). In thedetermination processing of upper or lower end playback type, when theplayback type is neither set as the upper end 2D subtitle playback typenor the lower end 2D subtitle playback type (step S24: No), is_SS_PG ofa PG stream identified by a PG stream number of a PSR2 is acquired fromstream registration information included in the stream selection table(step 25). Then, judgment is performed on whether a flag of the acquiredis_SS_PG indicates “1” and whether stereoscopic PG capability of b2 inPSR24 indicates “1” (step 26). If a result of the judgment in step S26is Yes, the playback type is set as the stereoscopic PG in which aleft-eye PG stream and a right-eye PG stream (step S27).

When the playback type is set as the stereoscopic PG, the stereoscopicplayback is performed by using packet identifier references that areincluded in the left-eye and right-eye stream entries of a piece ofstream registration information corresponding to the current streamnumber stored in PSR2, among a plurality of pieces of streamregistration information in the extension stream selection table. Morespecifically, the demultiplexing unit is caused to demultiplex TSpackets whose packet identifiers are indicated by the packet identifierreferences that are included in the left-eye and right-eye streamentries of a piece of stream registration information corresponding tothe current stream number stored in PSR2.

When the judgment result in step S26 is NO, the playback type is set as“1 plane+offsetPG” (step S28). When the playback type is set as “1plane+offsetPG”, the PG playback in the 1 plane+offset mode is executedby using an offset sequence indicated by the PG_text subtitle streamoffset sequence ID reference information in a piece of streamregistration information corresponding to the current stream numberstored in PSR2, among a plurality of pieces of stream registrationinformation in the extension stream selection table.

Here the offset sequence is explained. A plurality of offset sequencesto be used in the 1 plane+offset mode exist in the video access unit ofthe dependent-view video stream.

The video access unit of the dependent-view video stream is structuredas a sequence of a video access unit delimiter, a sequence parameterset, a picture parameter set, an MVC scalable nesting SEI message, afirst view component, a sequence end code, and a stream end code. TheMVC scalable nesting SEI message includes a user data container. Theuser data container is unregistered user data, and falls into threetypes: closed caption information; GOP structure map; and offsetmetadata. One of these types is indicated by the “type indicator” in theuser data container.

The offset metadata is a sequence list for the PG plane, IG plane, andBD-J plane, and is used for the offset setting while the presentationgraphics, text subtitle, and IG/BD-J plane are played back in the 1plane+offset mode. More specifically, the offset metadata indicates theoffset control on the PG plane, IG plane, and BD-J plane when thegraphics to be overlaid with the picture data is played back in the 1plane+offset mode.

The offset metadata should be stored in the MVC scalable nesting SEImessage in the starting video component of each GOP in the encodingorder of the dependent-view access unit. The offset metadata containsthe above-described plurality of offset sequences. The offset sequenceis a parameter sequence that indicates control parameters for each frameperiod in a group of pictures, where the control parameters are usedwhen the graphics are overlaid with each piece of picture data belongingto the group of pictures. The offset sequence is composed of as manycontrol parameters as the number indicated by the“number_of_displayed_frames_in_GOP”. The control parameter is composedof plane offset direction information and a plane offset value.

The plane offset direction information (“Plane_offset_direction”)indicates the direction of offset in the plane. When the plane offsetdirection information is set to a value “0”, it indicates the frontsetting in which the plane memory exists between the TV and the viewer,and in the left-view period, the plane is shifted rightward, and in theright-view period, the plane is shifted leftward. When the plane offsetdirection information is set to a value “1”, it indicates the behindsetting in which the plane memory exists behind the TV or the screen,and in the left-view period, the plane is shifted leftward, and in theright-view period, the plane is shifted rightward. When the plane offsetdirection information indicates the front setting, the Z-axis coordinateof the control parameter in the three-dimensional coordinate system is apositive coordinate. When the plane offset direction informationindicates the behind setting, the Z-axis coordinate of the controlparameter in the three-dimensional coordinate system is a negativecoordinate.

The plane offset value (“plane_offset_value”) indicates the amount ofdeviation in the horizontal direction, of the pixels constituting thegraphics, and indicates the offset value of the plane in units ofpixels.

When the playback type of PG is set as “1 plane+offsetPG”, an offsetsequence is extracted from the video decoder and the extracted offsetsequence is supplied to the shift unit, wherein the offset sequence tobe extracted is indicated by the PG_text subtitle stream offset sequenceID reference information in a piece of stream registration informationcorresponding to the current stream number, among a plurality of piecesof stream registration information stored in the SEI message of thedependent-view video stream.

This completes the explanation of the “procedure when playback conditionis changed” for the PG_text subtitle stream.

FIG. 28 is a flow chart showing a procedure of determination processingof upper or lower end playback type.

In the determination processing of upper and lower edges playback type,video_shift_mode of a PG stream identified by a PG stream number in thePSR2 is acquired from stream registration information included in theextension stream selection table (step S101). It is judged on whetherthe acquired video_shift_mode indicates “Down” and the video shift modeof the playback device in the PSR 32 indicates “Down” (step S102).

When a result of judgment in step S102 is YES, the playback type is setas the upper end 2D subtitle playback type (step S103). In this case, PGis played back in the upper end 2D subtitle playback mode. Specifically,the demultiplexing unit performs demultiplexing on a TS packet having apacket identifier indicated by a packet identifier reference included ina stream entry corresponding to a stream number of a current streamstored in the PSR2. Also, the shift unit shifts picture data, which isstored in each of the right-eye video plane and the left-eye videoplane, downward by 131 pixels.

When a result of the judgment in step S102 is No, it is judged onwhether the video_shift_mode acquired in step S101 indicates “Up” andthe video shift mode of the playback device in the PSR32 indicates “Up”(step S104). When a result of judgment in step S104 is YES, the playbacktype is set as the lower end 2D subtitle playback type (step S105). Inthis case, PG is played back in the lower end 2D subtitle playback mode.In the lower end 2D subtitle playback mode, the shift unit shiftspicture data, which is stored in each of the right-eye video plane andthe left-eye video plane, upward by 131 pixels.

This completes the description of the determination processing of upperor lower end playback type.

FIG. 29 is a flow chart showing the procedure for selecting a PG_textsubtitle stream that is optimum for the current playitem.

In step S30, it is checked for all PG_text subtitle streams whether thefollowing conditions (a), (b), and (c) are satisfied.

The conditions (a), (b), and (c) are defined as follows when thecheck-target PG stream is a PG stream i.

Condition (a): the playback device has the capability to decode the PGstream i.

Condition (b): PG_language_code of the PG stream i matches the languagesetting in the playback device. Here, the language setting in theplayback device is indicated by PSR17 in the register set.

The conditions (a), (b), and (c) are defined as follows when thecheck-target text subtitle stream is a text subtitle stream i.

Condition (a): the playback device has the capability to extend thecharacter code of the text subtitle stream i into a bit map.

Condition (b): the playback device has the capability to support thelanguage attribute of the text subtitle stream i.

Condition (c): the “textST_language_code” of the text subtitle stream imatches the language setting in the playback device.

After the checking, it is judged in step S31 whether or not the playbackdevice satisfies the condition (Z) described in the previous flow chart(playback of unsupported language). When the playback device does notsatisfy the condition (Z), the control goes to step S32 in which it isjudged whether or not there is a PG_text subtitle stream that satisfiesthe conditions (a), (b), and (c). When there are PG_text subtitlestreams that satisfy the conditions (a), (b), and (c), a PG_textsubtitle stream whose corresponding stream entry is placed first in thestream selection table is selected from among the PG_text subtitlestreams that satisfy the conditions (a) through (c), and the PG_textsubtitle stream number of the selected PG_text subtitle stream is set inPSR2 (step S33).

When there is no PG_text subtitle stream that satisfies the conditions(a), (b), and (c), the control goes to step S34 in which it is judgedwhether or not there is a PG_text subtitle stream that satisfies lessconditions. Here the less conditions in this context mean the conditions(a) and (b). Namely, in step S34, it is judged whether or not there is aPG_text subtitle stream that satisfies the conditions (a) and (b). Whenthere are PG_text subtitle streams that satisfy the conditions (a) and(b), a PG_text subtitle stream whose corresponding stream entry isplaced first in the Stream selection table is selected among the PG_textsubtitle streams that satisfy conditions (a) and (b), and the PG_textsubtitle stream number of the selected PG_text subtitle stream is set inPSR2 (step S36).

When there is no PG_text subtitle stream that satisfies the conditions(a) and (b), a value 0xFFF as a PG_text subtitle stream number is set inPSR2 (step S35). When it is judged in step S31 that the playback devicesatisfies the condition (Z), the control goes to step S37 in which it isjudged whether or not there is a PG_text subtitle stream that satisfiesanother less conditions. Here the “another less conditions” in thiscontext mean the conditions (a) and (c). Namely, in step S37, it isjudged whether or not there is a PG_text subtitle stream that satisfiesthe conditions (a) and (c).

When there are PG_text subtitle streams that satisfy the conditions (a)and (c), a PG_text subtitle stream whose corresponding stream entry isplaced first in the stream selection table is selected among the PG_textsubtitle streams that satisfy conditions (a) and (c), and the PG_textsubtitle stream number of the selected PG_text subtitle stream is set inPSR2 (step S38).

When there is no PG_text subtitle stream that satisfies the conditions(a) and (c), the control goes to step S39 in which it is judged whetheror not there is a PG_text subtitle stream that satisfies the condition(a). When there are PG_text subtitle streams that satisfy the condition(a), a PG_text subtitle stream whose corresponding stream entry isplaced first in the stream selection table is selected among the PG_textsubtitle streams that satisfy the condition (a), and the PG_textsubtitle stream number of the selected PG_text subtitle stream is set inPSR2 (step S40). When there is no PG_text subtitle stream that satisfiesthe condition (a), a value 0xFFF is set in PSR2 (step S35).

This completes the explanation of the procedure for selecting an optimumPG_text subtitle stream.

FIG. 30 is a flow chart showing the procedure which is to be executedwhen a stream change is requested by the set stream stereoscopic command(set stream SS command).

In step S41, it is judged whether the number “x” specified by an operandof the set stream stereoscopic command indicates a stream number of thePG stream (YES) or the text subtitle stream (NO). In step S42, it ischecked whether or not the PG stream corresponding to the number “x”(PGx) satisfies the following conditions (A) and (B).

Condition (A): The playback device has a capability to decode a PGstream that is identified by the number x.

Condition (B): The language attribute of the identified PG streammatches the language attribute of the playback device.

In step S43, it is checked whether or not the text subtitle streamcorresponding to the number “x” (textSTx) satisfies the followingconditions (A) and (B).

Condition (A): The playback device has a capability to extend thecharacter code of the text subtitle stream x into a bit map.

Condition (B): the playback device has the capability to support thelanguage attribute of the text subtitle stream x.

In step S44, it is checked whether or not the playback device satisfiesthe condition (Z), and then in step S45, it is judged whether or not thenumber is equal to or lower than the total number of stream entries inthe stream selection table and conditions (A) and (B) are satisfied.When the result of judgment in step S45 is affirmative, a PG_textsubtitle stream with a PG_text subtitle stream number corresponding tothe number x is selected, and the number x is set in PSR2 (step S46).

When the result of judgment in step S45 is negative, the controlproceeds to step S47 in which it is judged whether or not the number isequal to or lower than the total number of stream entries in the streamselection table and conditions (A) and (Z) are satisfied. When theresult of judgment in step S47 is affirmative, a PG_text subtitle streamwith a PG_text subtitle stream number corresponding to the number x isselected, and the number x is set in PSR2 (step S48).

When the result of judgment in step S47 is negative, the controlproceeds to step S49 in which it is judged whether or not the number xis 0xFFF. When it is judged that the number x is not 0xFFF, the value inPSR2 is maintained since it is determined that the stream selectiontable indicates that no PG_text subtitle stream has been permitted to beplayed back (step S50).

When it is judged that the number x is 0xFFF, a PG_text subtitle streamthat is optimum for the current playitem is selected (step S51). Thisselection of an optimum PG_text subtitle stream is performed in asimilar manner to the procedure shown in FIG. 29.

The process of subsequent steps S52 to S57 is unique to the 3D outputmode. Specifically, determination processing of upper or lower endplayback type is performed (step S52). In the determination processingof upper or lower end playback type, if the playback type is set asneither the upper end 2D subtitle playback type nor the lower end 2Dsubtitle playback type (step S53: No), is_SS_PG of a PG stream Xidentified by a PG stream number X is acquired from stream registrationinformation included in the extension stream selection table (step S54).Then, it is judged on whether a flag of the acquired is_SS_PG indicates“1” and whether stereoscopic PG capability of PSR24 indicates “1” (step55). If a result of the judgment in step 55 is Yes, the playback type isdetermined as a stereoscopic PG playback type (step 56). When the resultof the judgment in step S55 is NO, the playback type is set as “1plane+offset” (step S57).

FIG. 31 is a flow chart showing the procedure which is to be executedwhen a stream change is requested by the set stream command or by a useroperation requesting a stream number change. In this flow chart, in stepS58, the stream number specified by an operand of the set streamcommand, or the stream number specified by a user operation requesting astream number change, is set as the number x, and then the process ofsteps S41 through S57 is executed. The contents of steps S41 through S57are the same as those shown in FIG. 30, and thus the same referencenumbers are assigned thereto, and description thereof is omitted here.

<Determination of Current IG Stream and Playback Type Thereof>

A current IG stream whose stream number is to be stored in PSR0 isselected based on the output mode in PSR22, stereoscopic PG capabilityin PSR24, and “is_SS_IG”.

FIGS. 32A and 32B are flow charts showing the procedures for determiningthe current IG stream and the playback type thereof.

FIG. 32A is a flow chart showing the procedure for determining thecurrent IG stream when the playitem is changed and the playbackcondition of the playback device is changed. Among the steps shown inthis flow chart, the process of steps S61 to S65 is common to the 3Doutput mode and the 2D output mode, and the process of steps S64 to S67is unique to the 3D output mode.

In step S61, it is judged whether or not the number of entries in thestream selection table is “0”. When the number is “0”, the value in PSR0is maintained (step S64).

When it is judged in step S61 that the number of entries in the streamselection table is not “0”, the control proceeds to step S62 in which itis judged whether or not the number of entries in the stream selectiontable is equal to or greater than the value in PSR0. When the result ofjudgment in step S62 is affirmative, the value in PSR0 is maintained(step S65). When it is judged that the value in PSR1 is greater than thenumber of entries in the stream selection table, value “1” is set inPSR0 (step S63). Steps S64 through S67 that follow step S63 are uniqueto the 3D output mode. More specifically, steps S64 through S67 in the3D output mode are performed as follows. An “is_SS_IG” of an IG streamidentified by the IG stream number stored in PSR0 is obtained from thestream registration information in the extension stream selection table(step S64). It is judged whether or not the obtained “is_SS_IG” flag is“1” and the stereoscopic IG capability indicated by “b3” in PSR24 is “1”(step S65). When the result of judgment in step S65 is YES, the playbacktype is set as the stereoscopic IG (step S66). When the playback type isset as the stereoscopic IG, the stereoscopic playback is performed byusing packet identifier references that are included in the left-eye andright-eye stream entries of a piece of stream registration informationcorresponding to the current stream number stored in PSR0, among aplurality of pieces of stream registration information in the extensionstream selection table. More specifically, the demultiplexing unit iscaused to demultiplex TS packets whose packet identifiers are indicatedby the packet identifier references that are included in the left-eyeand right-eye stream entries of a piece of stream registrationinformation corresponding to the current stream number stored in PSR0.

When the judgment result in step S65 is NO, the playback type is set as“1 plane+offset” (step S67).

When the playback type is set as “1 plane+offsetIG”, the IG playback inthe 1 plane+offset mode is executed by using an offset sequenceindicated by the stereoscopic IG offset sequence ID referenceinformation in a piece of stream registration information correspondingto the current stream number stored in PSR0, among a plurality of piecesof stream registration information in the extension stream selectiontable. More specifically, an offset sequence is extracted from the videodecoder and the extracted offset sequence is supplied to the shift unit,wherein the offset sequence to be extracted is indicated by thestereoscopic IG offset sequence ID reference information in a piece ofstream registration information corresponding to the current streamnumber, among a plurality of pieces of stream registration informationstored in the SEI message of the dependent-view video stream.

FIG. 32B is a flow chart showing the procedure for setting PSR0 which isto be executed when a stream change is requested by the set streamstereoscopic command (set stream SS command), by the set stream command,or by a user operation requesting a stream number change.

When a stream change is requested by the set stream stereoscopic command(set stream SS command), by the set stream command, or by a useroperation requesting a stream number change, the stream number specifiedby an operand of the command, or the stream number specified by a useroperation, is set as the number x and the procedure is executed asfollows.

In step S71, it is judged whether or not the number of entries in thestream selection table is equal to or greater than the number x. Whenthe result of judgment in step S71 is affirmative, the value is set inPSR0 (step S74). When it is judged that the value x is greater than thenumber of entries in the stream selection table, value “1” is set inPSR0 (step S72). In the 3D output mode, the procedure is executed asfollows. An “is_SS_IG” of an IG stream identified by the IG streamnumber stored in PSR0 is obtained from the stream registrationinformation in the extension stream selection table (step S73). It isjudged whether or not the obtained “is_SS_IG” flag is “1” and thestereoscopic IG capability indicated by PSR24 is “1” (step S74). Whenthe result of judgment in step S74 is YES, the playback type is set asthe stereoscopic IG (step S75). When the judgment result in step S74 isNO, the playback type is set as “1 plane+offset” (step S76).

FIGS. 33A through 33C show what packet identifiers are output to thedemultiplexing unit by the combined stream registration sequence.

FIG. 33A shows the combined stream registration sequence used in theoperation as an example. The combined stream registration sequence iscomposed of three pieces of stream registration information provided inthe basic stream selection table and three pieces of stream registrationinformation provided in the extension stream selection table.

The three pieces of stream registration information provided in theextension stream selection table have stream numbers “1”, “2”, and “3”,respectively, and the stream attributes in the three pieces of streamregistration information have “English”, “Japanese”, and “Chinese” asthe language attributes, respectively. The stream registrationinformation provided in the basic stream selection table differs in thepacket identifier stored in the stream entry, from the streamregistration information provided in the extension stream selectiontable. Also, the stream registration information provided in theextension stream selection table contains (i) a packet identifier for abase-view PG stream for the B-D presentation mode, and (ii) a packetidentifier for a dependent-view PG stream.

FIG. 33B shows the setting of a stream number and the outputting of apacket identifier when such a combined stream registration sequence issupplied to playback device in which the language has been set to“Chinese” and the output mode has been set to the 2D output mode.

The arrows identified by signs “a1”, “a2”, and “a3” schematicallyindicate (i) the judgment on whether language settings match each other,(ii) the setting of a stream number in the stream number register, and(iii) the output of a packet identifier to the demultiplexing unit,respectively.

In the operation procedure of this example, it is judged whether thelanguage setting of the playback device matches the stream attributecontained in the stream registration information whose stream number is“3”, and it is judged that they match. As a result of this, the streamnumber “3” of this stream registration information is written into thestream number register. Also, the packet identifier written in thestream entry of the basic stream selection table is output to thedemultiplexing unit. Following this, a TS packet identified by thepacket identifier written in the stream entry of the stream registrationinformation whose stream number is “3” in the basic stream selectiontable is output to the decoder.

FIG. 33C shows the setting of a stream number and the outputting of apacket identifier when such a combined stream registration sequence issupplied to playback device in which the language has been set to“Chinese” and the output mode has been set to the B-D presentation mode.

The arrows identified by signs “a4”, “a5”, and “a6” schematicallyindicate (i) the judgment on whether language settings match each other,(ii) the setting of a stream number in the stream number register, and(iii) the output of a packet identifier to the demultiplexing unit,respectively.

In the operation procedure of this example, it is judged whether thelanguage setting of the playback device matches the stream attributecontained in the stream registration information whose stream number is“3”, and it is judged that they match. As a result of this, the streamnumber “3” of this stream registration information is written into thestream number register. Also, the packet identifier written in thestream entry of the basic stream selection table is output to thedemultiplexing unit. Following this, a pair of TS packets identified bya pair of packet identifiers written in the stream entry of the streamregistration information whose stream number is “1” in the extensionstream selection table are output to the decoder.

FIGS. 34A through 34C show what packet identifiers are output to thedemultiplexing unit by the combined stream registration sequence.

FIG. 34A shows the combined stream registration sequence used in theoperation as an example. The combined stream registration sequence iscomposed of three pieces of stream registration information provided inthe basic stream selection table and three pieces of stream registrationinformation provided in the extension stream selection table. The threepieces of stream registration information provided in the basic streamselection table have stream numbers “1”, “2”, and “3”, respectively, andall of the stream attributes in the three pieces of stream registrationinformation have “Chinese” as the language attributes.

The three pieces of stream registration information provided in theextension stream selection table have stream numbers “1”, “2”, and “3”,respectively, and all of the stream attributes in the three pieces ofstream registration information have “Chinese” as the languageattributes. The stream registration information provided in the basicstream selection table differs in the packet identifier stored in thestream entry, from the stream registration information provided in theextension stream selection table. Also, the stream registrationinformation provided in the extension stream selection table contains(i) a packet identifier for a left-eye PG stream for the B-Dpresentation mode, and (ii) a packet identifier for a right-eye PGstream for the B-D presentation mode.

FIG. 34B shows the setting of a stream number and the outputting of apacket identifier when such a combined stream registration sequence issupplied to playback device in which the language has been set to“Chinese” and the output mode has been set to the 2D output mode.

The arrows identified by signs “a1”, “a2”, and “a3” schematicallyindicate (i) the judgment on whether language settings match each other,(ii) the setting of a stream number, and (iii) the output of a packetidentifier to the demultiplexing unit, respectively.

In the stream selection procedure of this example, it is judged whetherthe language setting of the playback device matches the stream attributecontained in the stream registration information whose stream number is“1”, and it is judged that they match. As a result of this, the streamnumber “1” of this stream registration information is written into thestream number register. Also, the packet identifier written in thestream entry of the basic stream selection table is output to thedemultiplexing unit. Following this, a TS packet identified by thepacket identifier written in the stream entry of the stream registrationinformation whose stream number is “1” in the basic stream selectiontable is output to the decoder.

FIG. 34C shows the setting of a stream number and the outputting of apacket identifier when such a combined stream registration sequence issupplied to playback device in which the language has been set to“Chinese” and the playback type has been set to the 1 plane+Offset type.

The arrows identified by signs “a4”, “a5”, and “a6” schematicallyindicate (i) the judgment on whether language settings match each other,(ii) the setting of a stream number in the stream number register, and(iii) the output of a packet identifier to the demultiplexing unit,respectively.

In the operation procedure of this example, it is judged whether thelanguage setting of the playback device matches the stream attributecontained in the stream registration information whose stream number is“1”, and it is judged that they match. As a result of this, the streamnumber “1” of this stream registration information is written into thestream number register. Also, the packet identifier written in thestream entry of the basic stream selection table is output to thedemultiplexing unit. Following this, a pair of TS packets identified bya pair of packet identifiers written in the stream entry of the streamregistration information whose stream number is “1” in the extensionstream selection table are output to the decoder.

According to the present embodiment as described above, the extensionstream selection table includes a video shift mode that defines savingof subtitle display region in correspondence with a stream number.Accordingly, when the playback section changes, or when a request forchanging the stream is received, a stream selection procedure isexecuted. When a new stream number is set in a stream number register, avideo shift mode corresponding to the set new stream number is providedwith the playback device. With this structure, it is possible to realizecontrol in which a display region of a subtitle is saved in the upperend of the screen in a playback section and a display region of asubtitle is saved in the lower end of the screen in another playbacksection.

The cinema scope size (1:2.35) is generally used for the aspect ratio ofvideo of movies. In the case where a video is stored in an optical discsuch as a BD-ROM, a main feature video is disposed in the center of anHD video having the aspect ratio of 16:9 without changing the aspectratio, and a black frame is inserted into each of the upper side and thelower side of the HD video. Accordingly, with the above structure, it ispossible to display subtitles in a large subtitle display regiongenerated by collecting black frames located above and below the mainfeature video to one of the upper end and the lower end of the videoplane. This can improve the use efficiency of the screen, therebyimproving the stereoscopic effect.

Modification Example

As a modification example of the present embodiment, the followingdescribes a method of shifting upward or downward not only picture datastored in the video plane memory but also subtitles stored in the PGplane memory so as to overlay the picture data with the subtitles.

FIGS. 35A through 35C show the stream registration sequences in theextension stream selection table according to the present modificationexample. FIG. 35B shows the internal structure of the PG streamregistration sequence.

In the present modification example, the stream registration informationof the PG stream additionally includes a “PG shift value video shiftupward (PG_v_shift_value_for_Up)” and a “PG shift value video shiftdownward (PG_v_shift_value_for_Down)”.

The “PG shift value in video shift upward (PG_v_shift_value_for_Up)”represents an amount of downward shift of subtitle data stored in the PGplane memory in the case where the video shift mode is set as “Up” and adisplay region of subtitles of a PG_text subtitle stream is saved in thelower ends of the video plane.

The “PG shift value in video shift downward (PG_v_shift_value_for_Down)”represents an amount of upward shift of subtitle data stored in the PGplane memory in the case where the video shift mode is set as “Down” anda display region of subtitles of a PG_text subtitle stream is saved inthe upper ends of the video plane.

These values are set in PSR33 shown in FIG. 37. The shift amount shownby the PSR33 includes a plane shift amount in video shift upward and aplane shift amount in video shift downward for each plane. For example,the PSR33 includes “PG_shift_value_for_UP” and “PG_shift_value_for_Down”for a PG plane. These values are set by acquiringPG_v_shift_value_for_Up and PG_v_shift_value_for_Down of a current PGstream selected by stream switching from stream registration informationin the extension stream selection table.

FIG. 36 shows the circuit structure for overlaying data output from thedecoder model and outputting the overlaid data in the upper end 2Dsubtitle playback mode and the lower end 2D subtitle playback mode. Inthe present modification example, in the upper end 2D subtitle playbackmode and the lower end 2D subtitle playback mode, in accordance with thesetting of the PSR32, pixel shift of the video plane is performed upwardor downward by 131 pixels for each of the left-eye view and theright-eye view. Also, in accordance with the value ofPG_shift_value_for_Up or the value of PG_shift_value_for_Down set in thePSR33, pixel shift of the PG plane is performed upward or downward foreach of the left-eye view and the right-eye view. Then, layer overlayingis performed on these pixels.

Specifically, when the video_shift_mode in the PSR32 is set as “Up”, apicture output from the video plane memory is shifted upward by 131pixels, and a subtitle output from the PG plane is shifted downward bythe number of pixels set in the PG_shift_value_for_Up in the PSR33, andlayer overlaying is performed on the picture and subtitle, as shown inFIG. 38A. On the other hand, when the video_shift_mode in the PSR32 isset as “Down”, a picture output from the video plane memory is shifteddownward by 131 pixels, and a subtitle output from the PG plane isshifted upward by the number of pixels set in thePG_shift_value_for_Down in the PSR33, and layer overlaying is performedon the picture and subtitle, as shown in FIG. 38B.

Here, in the present modification example, as shown in FIG. 39, in thecase where the video_shift_mode indicates “Up” or “Down”, plane shiftresults in a cropped region. Accordingly, there only needs to make arestriction such that no subtitle data is in the cropped region. Inother words, as shown in the left side of FIG. 39, since a region otherthan a region surrounded by a dashed line has a possibility to becropped, a display position of the PG is restricted such that nosubtitle data is displayed on the region other than the regionsurrounded by the dashed line. The coordinate of the region isrepresented by (0,PG_v_shfit_value_for_Down),(0,height+PG_v_sfhit_value_for_Up), (width,PG_v_shfit_value_for_Down),and (width,height+PG_v_sfhit_value_for_Up). For example, ifPG_v_sfhit_value_for_Up indicates −a and PG_v_sfhit_value_for_Downindicates+b, the region is represented by (0,b), (0,height−a),(width,b), and (width,height−a). As the constraint conditions for PG,the display position is restricted so as not to go beyond the aboveregion, the display position to which the size of an object to bedisplayed is added is restricted so as not to go beyond the aboveregion, the display position of the window is restricted so as not to gobeyond the above region, and the display position of the window to whichthe window size is added is restricted so as not to go beyond the aboveregion, for example. Such constraint conditions can prevent display of apartially lacking.

Embodiment 2

The following describes Embodiment 2 of the present invention.

In the present embodiment, a method is described for realizing 3D videohaving an appropriate depth depending on the screen size of a TVconnected to the 2D/3D playback device.

In the case of 3D video with use of the parallax images, the screen sizeaffects the sense of depth of 3D video, as shown in the left side ofFIG. 40. This is due to the difference value between the left-eye videoand the right eye video that varies depending on the screen size of theTV. Suppose that, for example, in the case where a left video and aright video are created so as to realize the most appropriate width fora 50-inch TV as shown in the left side of FIG. 40. In such a case, it ispossible to realize the most appropriate viewing for a 50-inch TV.However, the difference value between the left-eye video and the righteye video is small for a TV smaller than the 50-inch TV, and as a resulta video that is not powerful and does not have much width is displayedin such a TV. On the other hand, the difference is too large for a TVlarger than the 50-inch TV, and this causes the user to have aneyestrain. In view of this, it is preferable to apply an offset valuefor correcting the screen size to each of the left-eye plane and theright eye plane for output to the TV, as shown in the right side of FIG.40. For example, in the case where the left-eye video and the right eyevideo are optimized for the 50-inch TV as shown in FIG. 40, an offsetvalue is set for a 32-inch TV so as to increase the sense of depth foroutput to the TV. An offset value is set for a 100-inch TV so as todecrease the sense of depth for output to the TV. Setting of an offsetvalue indicates, like the 1 plane+offset method, the last plane outputfrom the player is shifted based on an offset value, and is cropped. Anoffset value to be applied to this last plane of the player is referredto as an “output offset correction value”. The following describes aspecific method.

Firstly, the data structure is described. The basic parts of the datastructure are the same as those for storing 3D videos described in theabove embodiments, and accordingly additional parts or different partsfrom the above embodiments are mainly described here.

In a file such as an index file, a playlist file, and an AV streaminformation file, a table as shown in FIG. 41A is stored. In this table,a plurality of pieces of screen size information are registered, each ofwhich includes a TV inch and an output offset correction value that aregrouped into pairs. In FIG. 41A, the inch number is defined for each 10inches. Alternatively, the inch number may be defined for each arbitraryinch in accordance with a predetermined standard. Further alternatively,the user may define the inch number. It may be employed to prepare sometables as shown in FIG. 41A, and only reference IDs of these tables areregistered in the file such as the index file, the playlist file, andthe AV stream information file. It may be employed to prepare a functionfor determining an offset value depending on the inch number as shown inthe right side of FIG. 41B.

The table may include, in addition to the pairs of TV inch and outputoffset correction values, a value of the optimal TV size(assumed_TV_size_when authoring) indicating an inch a created contenttargets. The use of the values of the optimal TV size makes it possibleto perform various types of correction processing. For example, in thecase where display is performed by a TV having an optimal inch size orgreater, it is possible to perform processing such as displaying imageshaving the optimal inch size on the center of the screen of the TV anddisplaying a black frame around a video, as shown in FIG. 42.

Next, the playback device relating to the preset embodiment isdescribed. The playback device includes, as shown in FIG. 43, a PSR35that is a system parameter for storing an output offset correction valueand an output offset correction value application unit. The playbackcontrol unit acquires the screen size (inch number) of a TV to beconnected with the playback device via an HDMI cable or the like,identifies an output offset correction value corresponding to the screensize based on the table shown in FIG. 41, and stores the identifiedoutput offset correction value in the PSR35. The output offsetcorrection value application unit refers to the value stored in thePSR35, and set an offset value for a plane the left-eye video and theright-eye video that are overlaid by the plane addition unit, using avalue of the PSR35.

Instead of storing an output offset correction value in the PSR35, thestructure may be employed in which the screen size is stored in thePSR35 and the output offset correction value application unit identifiesan output offset correction value with reference to the table shown inFIG. 41.

Note that the output offset correction value may be adjusted dependingon a user who is watching the video. For example, since an infant has anarrow distance between left and right eyes, the smaller differencebetween a left-eye video and a right eye video is preferable. In view ofthis, an “output offset correction value α” for correcting the outputoffset correction value is prepared. The output offset correction valueapplication unit performs offset correction processing with use of avalue resulting from multiplying the offset correction value by the“output offset correction value α”. Specifically, the processing isrealized with use of the structure shown in FIG. 44. FIG. 44 shows aPSR36 in which the output offset correction value α is stored. Theplayback control unit or the program execution unit sets the value onthe PSR36 via the menu screen, the OSD screen of the player, or thelike. For example, in order to decrease the depth for a child user, itis possible to decrease the depth by setting a value greater than 1. Theoutput offset correction value application unit refers to the PSR35 andthe PSR36, and applies offset on the plane with use of a value resultingfrom multiplying the output offset correction value by the output offsetcorrection value α. As a result, it is possible to adjust the sense ofdepth in accordance with a user's preference.

It may be possible to employ the structure in which the “output offsetcorrection value α” is set on the menu screen of the BD program byselecting one of three modes “weak”, “normal”, and “strong” for thedepth of 3D.

The “output offset correction value α” may be stored for each of the SEImessage of a video stream, the descriptor of the PMT packet, theplayitem, or the like, and may be changed depending on the scene. Withsuch a structure, it is possible to set an “output offset correctionvalue α” having a greater value for a scene having a large depth, forexample.

In the present embodiment, the output offset amount correction value ischanged depending on the screen size of TV. Alternatively, the outputoffset amount correction value or the output offset correction value αmay be changed depending on the distance from the TV to the user. Inthis case, the following structure may be employed. Glasses for 3Dviewing measures the distance from the screen of the TV to the glasses,the TV acquires the distance, and then the TV notifies the playbackdevice of the distance via an HDMI cable.

In the present embodiment, the output offset amount correction value ischanged depending on the screen size of TV. Alternatively, the projectormay measure the screen size in the following methods because theprojector cannot recognize the size of the screen. According to one ofthe methods, the projector outputs a laser to the screen such asinfrared light, the distance is measured with use of the flashback ofthe infrared light from the screen, and the screen size is calculatedwith use of the optical parameter of the lens. According to another oneof the methods, the length of a “line segment” is displayed on theprojector, and the user measures the length of the line segment on thescreen inputs the length via the OSD of the projector. The projector cancalculate the length of the screen depending on the length of the linesegment on the screen.

According to the present embodiment as described above, it is possibleto achieve an optimal stereoscopic effect suitable for each screen sizeby performing offset processing for changing the difference valuebetween the left-eye video and the right-eye video depending on thescreen size for video display.

Embodiment 3

Embodiment 3 relates to an improvement of the internal structure of thestereoscopic interleaved stream file.

Here, as a premise of the present embodiment, files in the UDF filesystem will be explained briefly. The UDF file is composed of aplurality of Extents managed by the file entry. The “file entry”includes a “descriptor tag”, an “ICB tag”, and an “allocationdescriptor”.

The “descriptor tag” is a tag identifying, as a “file entry”, the fileentry which includes the descriptor tag itself. The descriptor tag isclassified into a file entry descriptor tag, a space bit map descriptortag, and so on. In the case of a file entry descriptor tag, “261”, whichindicates “file entry” is written therein.

The “ICB tag” indicates attribute information concerning the file entryitself.

The “allocation descriptor” includes a Logical Block Number (LBN)indicating a recording position of an Extent constituting a low-orderfile under a directory. The allocation descriptor also includes datathat indicates the length of the Extent. The high-order two bits of thedata that indicates the length of the Extent are set as follows: “00” toindicate an allocated and recorded Extent; “01” to indicate an allocatedand not-recorded Extent; and: “11” to indicate an Extent that followsthe allocation descriptor. When a low-order file under a directory isdivided into a plurality of Extents, the file entry should include aplurality of allocation descriptors in correspondence with the Extents.

It is possible to detect an address of an Extent constituting a streamfile by referring to the allocation descriptor in the file entrydescribed above.

The following describes the files in various types that are used in thepresent embodiment.

<Stereoscopic Interleaved Stream File (FileSS)>

The stereoscopic interleaved stream file (FileSS) is a stream file(2TS-interleaved file) in which two TSs are interleaved, and isidentified by a five-digit integer value and an extension (ssif)indicating an interleave-format file for stereoscopic playback. Thestereoscopic interleaved stream file is composed of Extent SS[n]. TheExtent SS[n] (also referred to as “EXTSS[n]”) is identified by the indexnumber “n”. The index number “n” increments in order starting from thetop of the stereoscopic interleaved stream file.

Each Extent SS[n] is structured as a pair of a dependent-view data blockand a base-view data block.

The dependent-view data block and base-view data block constituting theExtent SS[n] are a target of cross reference by the file 2D, file base,and file dependent. Note that the cross reference means that a piece ofdata recorded on a recording medium is registered as an Extent of aplurality of files in the file entries thereof. In the presentembodiment, the starting addresses and continuation lengths of thedependent-view data block and base-view data block are registered in thefile entries of the file 2D, file base, and file dependent.

<File Base (FileBase)>

The file base (FileBase) is a virtual stream file that is presumed to“store” a main TS specified by the extent start point information in theclip information corresponding to the file 2D. The file base (FileBase)is composed of at least one Extent 1[i] (also referred to as “EXT1[i]”).The Extent 1[i] is the i^(th) Extent in the file base, where “i” is anindex number of the Extent and is incremented starting from “0” at thetop of the file base. The file base is a virtual stream file used totreat the stereoscopic interleaved stream file, which is a 2TS-file, asa 1TS-file. The file base is generated in a virtual manner by buildingits file entry in the memory of the playback device.

In the actual reading, the file base is identified by performing a fileopen using a file name of the stereoscopic interleaved stream file. Morespecifically, when the file open using a file name of the stereoscopicinterleaved stream file is called, the middleware of the playback devicegenerates, in the memory, a file entry identifying an Extent in the filebase, and opens the file base in a virtual manner. The stereoscopicinterleaved stream file can be interpreted as “including only one TS”,and thus it is possible to read a 2TS stereoscopic interleaved streamfile from the recording medium as a 1TS file base.

When only a base-view data block is to be read in the B-B presentationmode, only the Extents constituting the file base become the target ofthe reading. Even if the mode is switched from the B-B presentation modeto the B-D presentation mode, both the dependent-view data block and thebase-view data block can be read by extending the reading range from theExtents constituting the file base to the Extents constituting thestereoscopic interleaved stream file. Thus, with this arrangement, theefficiency of the file reading is not decreased.

<File Dependent (FileDependent)>

The file dependent (FileDependent) is a stream file that is presumed to“store” a sub-TS, and is composed of Extent 2[i] (also referred to as“EXT2[i]”). The Extent 2[i] is the i^(th) Extent in the file dependent,where “i” is an index number of the Extent and is incremented startingfrom “0” at the top of the file dependent. The file dependent is avirtual stream file used to treat the stereoscopic interleaved streamfile, which is a 2TS-file, as a 1TS-file storing the sub-TS. The filedependent is generated in a virtual manner by building its file entry inthe memory of the playback device.

The dependent-view video stream is attached with and accessed with useof a file name that is represented by a number generated by adding “1”to the five-digit integer representing the file name of the stereoscopicinterleaved stream file. The recording medium stores a dummy file, andthe “number generated by adding 1”, namely, the identification number ofthe dependent-view video stream, is attached to the dummy file. Notethat the dummy file is a file that stores no Extent, namely, substantialinformation, but is attached with only a file name. The dependent-viewvideo stream is treated as being stored in the dummy file.

<File 2D (File2D)>

The file 2D (File2D) is a 1TS stream file storing a main TS that isplayed back in the 2D output mode, and is composed of the Extent 2D. Thefile 2D is identified by a five-digit integer value and an extension(ssif) indicating an interleave-format file for stereoscopic playback.

FIG. 45 shows the correspondence between the file 2D/file base and thefile dependent.

In FIG. 45, the first row shows a file 2D/file base 00001.m2ts and afile dependent 00002.m2ts. The second row shows Extents that storedependent-view data blocks and base-view data blocks. The third rowshows a stereoscopic interleaved stream file 00001.ssif.

The dotted arrows h1, h2, h3, and h4 show the files to which ExtentsEXT1[i] and EXT2[i] belong, the belongingness being indicated by theallocation identifiers. According to the belongingness guided by thearrows h1 and h2, Extents EXT1[i] and EXT1[i+1] are registered asExtents of the file base 00001.m2ts.

According to the belongingness guided by the arrows h3 and h4, ExtentsEXT2[i] and EXT2[i+1] are registered as Extents of the file dependent00002.m2ts.

According to the belongingness guided by the arrows h5, h6, h7, and h8,Extents EXT1[i], EXT2[i], EXT1[i+1], and EXT2[i+1] are registered asExtents of 00001.ssif. As understood from this, Extents EXT1[i] andEXT1[i+1] have the duality of belonging to 00001.ssif and 00001.m2ts.The extension “ssif” is made of capital letters of StereoScopicInterleave File, indicating that the file is in the interleave formatfor stereoscopic playback.

Here, a pair of an Extent constituting the file base and an Extentconstituting the file dependent that are both identified by the sameExtent identifier is called an “interleave Extent unit”. In the exampleshown in FIG. 45, a pair of EXT1[i] and EXT2[i] that are both identifiedby an Extent identifier “i” is an interleave Extent unit [i]. Also, apair of EXT1[i+1] and EXT2[i+1] that are both identified by an Extentidentifier “i+1” is an interleave Extent unit [i+1]. In a random accessto a stereoscopic interleaved stream file, it is necessary to ensurethat an interleave Extent unit identified by the Extent identifier isread from the recording medium completely at once.

FIGS. 46A through 46C show the correspondence between the interleavedstream file and file 2D/file base.

The third row in FIG. 46A shows the internal structure of theinterleaved stream file. The stereoscopic interleaved stream file iscomposed of Extents EXT1[1] and EXT1[2] storing base-view data blocksand EXT2[1] and EXT2[2] storing dependent-view data blocks, wherein theyare arranged alternately in the interleave format.

The first row in FIG. 46A shows the internal structure of the file2D/file base. The file 2D/file base is composed of only Extents EXT1[1]and EXT1[2] storing base-view data blocks, among the Extentsconstituting the interleaved stream file shown in the third row. Thefile 2D/file base and the interleaved stream file have the same name,but different extensions.

The second row in FIG. 46A shows the internal structure of the filedependent. The file dependent is composed of only Extents EXT2[1],EXT2[2], and EXT2[3] storing dependent-view data blocks, among theExtents constituting the interleaved stream file shown in the third row.The file name of the file dependent is a value higher by “1” than thefile name of the interleaved stream file, and they have differentextensions.

Not all playback devices necessarily support the 3D playback system.Therefore, it is preferable that even an optical disc including a 3Dimage supports a 2D playback. It should be noted here that the playbackdevices supporting only the 2D playback do not identify the datastructure extended for the 3D. The 2D playback devices need to accessonly the 2D playlists and 2D streams by using a conventionalidentification method provided to the 2D playback devices. In view ofthis, the base-view video streams are stored in a file format that canbe recognized by the 2D playback devices.

According to the first method, the main TS is assigned with the samefile name as that in the 2D playback system so that the above-describedreferencing of playlist information can be realized, that is to say, sothat the main TS can be used in the 2D playback as well, and streamfiles in the interleave format have a different extension. FIG. 46Bshows that files “00001.m2ts” and “00001.ssif” are coupled with eachother by the same file name “00001”, although the former is in the 2Dformat and the latter is in the 3D format.

In a conventional 2D playback device, the playlist refers to only the AVclips the main TS, and therefore the 2D playback device plays back onlythe file 2D. On the other hand, in a 3D playback device, although theplaylist refers to only the file 2D storing the main TS, when it finds afile that has the same identification number and a different extension,it judges that the file is a stream file in the interleave format forthe 3D image, and outputs the main TS and sub-TS.

The second method is to use different folders. The main TSs are storedin folders with conventional folder names (for example, “STREAM”), butsub-TSs are stored in folders with folder names unique to 3D (forexample, “SSIF”), with the same file name “00001”. In the 2D playbackdevice, the playlist refers to only files in the “STREAM” folder, but inthe 3D playback device, the playlist refers to files having the samefile name in the “STREAM” and “SSIF” folders simultaneously, making itpossible to associate the main TS and the sub-TS.

The third method uses the identification numbers. That is to say, thismethod associates the files based on a predetermined rule regarding theidentification numbers. For example, when the identification number ofthe file 2D/file base is “00001”, the file dependent is assigned withidentification number “00002” that is made by adding “1” to theidentification number of the file 2D, as shown in FIG. 46C. However, thefile system of the recording medium treats the file dependent, which isassigned with a file name according to the rule, as a non-substantialdummy file. This is because the file dependent is, in the actuality, thestereoscopic interleaved stream file. The file names having beenassociated with each other in this way are written into (i) the streamregistration information in the basic stream selection table and (ii)the sub-clip entry ID reference (ref_to_subclip_entry_id) in the streamregistration information in the extension stream selection table. On theother hand, the playback device recognizes a file name, which is a valuehigher by “1” than the file name written in the sub-clip entry IDreference, as the file name of the dummy file, and performs the processof opening the file dependent in a virtual manner. This ensures that thestream selection procedure reads, from the recording medium, the filedependent that is associated with other files in the above-describedmanner.

The clip information files are identified by the same rule as above.

This completes the description of the file 2D, file base, and filedependent.

The following explains the data blocks in detail.

<Base-view Data Block>

The base-view data block (B[i]) is the i^(th) data in the main TS. Notethat the main TS is a TS specified as the main element of the main pathby the clip information file name information of the current playiteminformation. The “i” in B[i] is an index number that is incrementedstarting from “0” corresponding to the data block at the top of the filebase.

The base-view data blocks fall into those shared by the file base andthe file 2D, and those not shared by the file base and the file 2D.

The base-view data blocks shared by the file base and the file 2D andthe base-view data blocks unique to the file 2D become the Extents ofthe file 2D, and they are set to have a length that does not cause abuffer underflow in the playback device. The starting sector address ofthe base-view data blocks is written in the allocation descriptor in thefile entry of the file 2D.

The base-view data blocks unique to the file base, which are not sharedby the file 2D, do not become the Extents of the file 2D, and thus theyare not set to have a length that does not cause an underflow in asingle buffer in the playback device. The base-view data blocks are setto have a smaller size, namely, a length that does not cause anunderflow in a double buffer in the playback device.

The starting sector addresses of the base-view data block unique to thefile base are not written in the allocation descriptor in the fileentry. Instead of this, the starting source pocket in the base-view datablock is pointed to by the extent start point information in the clipinformation of the clip information file corresponding to the main TS.Therefore, the starting sector address of a base-view data block uniqueto the file base needs to be obtained by using (i) the allocationdescriptor in the file entry of the stereoscopic interleaved stream fileand (ii) the extent start point information in the clip information.

<Dependent-view Data Block>

The dependent-view data block (D[i]) is the i^(th) data in the sub-TS.Note that the sub-TS is a TS specified as the main element of thesub-path by the stream entry in the stream registration sequence in theextension stream selection table corresponding to the current playiteminformation. The “i” in D[i] is an index number that is incrementedstarting from “0” corresponding to the data block at the top of the filedependent.

The dependent-view data blocks become the Extents of the file dependent,and are set to have a length that does not cause an underflow in adouble buffer in the playback device.

Also, in the continuous regions in the recording medium, adependent-view data block is disposed before a base-view data block thatis played back in the same playback time together the dependent-viewdata block. For this reason, when the stereoscopic interleaved streamfile is read, the dependent-view data block is read before thecorresponding base-view data block, without fail.

The starting sector addresses of the dependent-view data blocks are notwritten in the allocation descriptor in the file entry of the file 2Dsince the dependent-view data blocks are not shared by the file 2D.Instead of this, the starting source pocket in the dependent-view datablock is pointed to by the extent start point information in the clipinformation. Therefore, the starting sector address of a dependent-viewdata block needs to be obtained by using (i) the allocation descriptorin the file entry of the file 2D and (ii) the extent start pointinformation in the clip information.

<Classification of Extent>

As described above, the Extents of the file 2D fall into those shared bythe file base, and those not shared by the file base.

Suppose here that the Extents of the file 2D are B[0], B[1], B[2],B[3]2D, and B[4]2D, and that the Extents of the file base are B[0],B[1], B[2], B[3]ss, and B[4]ss. Of these, B[0], B[1], and B[2] arebase-view data blocks shared by the file base. B[3]2D and B[4]2D arebase-view data blocks unique to the file 2D, not shared by the filebase.

Also, B[3]ss and B[4]ss are base-view data blocks unique to the filebase, not shared by the file 2D.

The data of B[3]2D is bit-for-bit same as data of B[3]ss. The data ofB[4]2D is bit-for-bit same as data of B[4]ss.

The data blocks B[2], B[3]2D, and B[4]2D in the file 2D constituteExtents (big Extents) having a large continuation length immediatelybefore a position at which a long jump is caused. In this way, bigExtents can be formed immediately before a long jump in the file 2D.Accordingly, even when a stereoscopic interleaved stream file is playedback in the 2D output mode, there is no need to worry an occurrence ofan underflow in the read buffer.

The file 2D and the file base have sameness, although being partiallydifferent in Extents. Therefore, the file 2D and the file base aregenerically called “file 2D/file base”.

FIG. 47 shows correspondence among the stereoscopic interleaved streamfile, file 2D, file base, and file dependent. The first row in FIG. 47shows the file 2D, the second row shows data blocks recorded on therecording medium, the third row shows the stereoscopic interleavedstream file, the fourth row shows the file base, and the shows the filedependent.

The data blocks shown in the second row are D[1], B[1], D[2], B[2],D[3], B[3]ss, D[4], B[4]ss, B[3]2D, and B[4]2D. The arrows ex1, ex2,ex3, and ex4 show the belongingness in which, among these data blocks,data blocks B[1], B[2], B[3]2D, and B[4]2D constitute the Extents of thefile 2D.

The arrows ex5 and ex6 show the belongingness in which D[1], B[1], D[2],B[2], D[3], B[3]ss, D[4], and B[4]ss constitute the Extents of thestereoscopic interleaved stream file.

The fourth row shows that, among these data blocks constituting thestereoscopic interleaved stream file, B[1], B[2], B[3]ss, and B[4]ssconstitute the Extents of the file base. The fifth row shows that, amongthe data blocks constituting the stereoscopic interleaved stream file,D[1], D[2], D[3], and D[4] constitute the Extents of the file dependent.

FIG. 48 shows the 2D playlist and 3D playlist. The first row shows the2D playlist information. The second row shows the base-view data blocks.The third row shows the 3D playlist. The fourth row shows thedependent-view data blocks.

The arrows rf1, rf2, and rf3 show a playback path generated by combiningthe extension “m2ts” and a file name “00001” described in“clip_information_file_name” in the playitem information of the 2Dplaylist information. In this case, the playback path on the base-viewside is constituted from data blocks B[1], B[2], and B[3]2D.

The arrows rf4, rf5, rf6, and rf7 show a playback path specified by theplayitem information of the 3D playlist information. In this example,the playback path on the base-view side is constituted from data blocksB[1], B[2], B[3]ss, and B[4]ss.

The arrows rf8, rf9, rf10, and rf11 show a playback path specified bythe sub-playitem information of the 3D playlist information. In thisexample, the playback path on the dependent-view side is constitutedfrom data blocks D[1], D[2], D[3], and D[4]. These data blocksconstituting the playback paths specified by the playitem informationand the sub-playitem information can be read by opening files that aregenerated by combining the extension “ssif” and file names written in“clip_information_file_name” in the playitem information.

As shown in FIG. 48, the clip information file name information in the3D playlist and the clip information file name information in the 2Dplaylist have file names in common. Accordingly, the playlistinformation can be written to include description that is common to the3D playlist and the 2D playlist (see as signs df1 and df2 indicate) soas to define the 3D playlist and the 2D playlist. Accordingly, onceplaylist information for realizing the 3D playlist is written: theplaylist information functions as the 3D playlist when the output modeof the playback device is the stereoscopic output mode; and the playlistinformation functions as the 2D playlist when the output mode of theplayback device is the 2D output mode. The 2D playlist and the 3Dplaylist shown in FIG. 48 have in common a piece of playlistinformation, which is interpreted as the 2D playlist or the 3D playlistdepending on the output mode of the playback device that interprets thepiece of playlist information. This reduces the amount of time andeffort made by a person in charge of authoring.

When main TSs and sub-TSs are stored in the stereoscopic interleavedstream file, a file name of the file 2D is written in“clip_information_file_name” in the playitem information of the 2Dplaylist, and a file name of the file base is written in“clip_information_file_name” in the playitem information of the 3Dplaylist. Since the file base is a virtual file and its file name is thesame as that of the stereoscopic interleaved stream file, the file nameof the stereoscopic interleaved stream file can be written in“clip_information_file_name” in the playitem information. A file name ofthe file dependent is written in “ref_to_subclip_entry_id” in the streamregistration information in the extension stream selection table. Thefile name of the file dependent is created by adding “1” to theidentification number of the stereoscopic interleaved stream file.

As described above, base-view and dependent-view data blocks are storedin one stereoscopic interleaved stream file, and the stereoscopicinterleaved stream file can be opened as a file of any of the file 2D,file base, and file dependent. With this structure, the decoder cantreat the stereoscopic interleaved stream file in the same manner as aregular stream file. Thus the storage method of the base-view anddependent-view video streams can be positively used for the storage ofthe stereoscopic interleaved stream file.

Next, the internal structure of the clip information file will bedescribed in detail.

FIGS. 49A through 49D show the internal structure of the clipinformation file.

FIG. 49A shows the clip information file for 2D. FIG. 49B shows the clipinformation file for 3D. These clip information files include “clipinformation”, “sequence information”, “program information”, and“characteristic point information”.

The “clip information” is information indicating, for each ATC sequence,what type of AV clip each source packet sequence stored in the streamfile is.

The “sequence information” indicates, for each ATC sequence, information(ATC sequence information) that indicates what type of ATC sequence oneor more source packet sequences stored in the stream file are. The ATCsequence information includes: information indicating, by the sourcepacket number, where the source packet being the start point of the ATCexists; offsets between the STC sequence identifiers and the ATCsequence identifiers; and STC sequence information corresponding to eachof a plurality of STC sequences. Each piece of STC sequence informationincludes: a packet number of a source packet storing the PCR of the STCsequence in concern; information indicating where in the STC sequencethe source packet being the start point of the STC sequence exists; andthe playback start time and the playback end time of the STC sequence.

The “program information” indicates the program structures of the mainTS and sub-TSs managed as “AV clips” by the clip information file. Theprogram information indicates what types of ESs are multiplexed in theAV clip. More specifically, the program information indicates what typesof packet identifiers the ESs multiplexed in the AV clip have, andindicates the encoding method. Thus the program information indicatesthe encoding method, such as MPEG2-video or MPEG4-AVC, that is used tocompress-encode the video stream.

The “characteristic point information” is information indicating, foreach ES, where the characteristic points of a plurality of ESsmultiplexed in the AV clip exist. The information indicating thecharacteristic point for each ES is called a “basic entry map”.

What becomes the characteristic point is different for each type ofstream. In the case of the base-view and dependent-view video streams,the characteristic point is the access unit delimiter that indicates theI-picture-type view component that is located at the start of the openGOP and closed GOP. In the case of the audio stream, the characteristicpoint is the access unit delimiter indicating the start positions of theaudio frames that exist at regular intervals, for example, every onesecond. In the case of the PG and IG streams, the characteristic pointis the access unit delimiter indicating the start positions of thedisplay sets (display set of epoch start, display set of acquisitionpoint) that are provided with all the functional segments necessary forthe display, among the display sets of the graphics streams.

The ATC sequence and the STC sequence differ in how they represent thecharacteristic point. The ATC sequence represents the characteristicpoint by the source packet number. The STC sequence represents thecharacteristic point by using the PTS that indicates the time point onthe STC time axis.

In view of the above-described differences, the basic entry map for eachES is composed of a plurality of entry points. More specifically, ineach entry point constituting the entry map, a source packet number thatindicates the location of the characteristic point in the ATC sequenceis associated with a PTS that indicates the location of thecharacteristic point in the STC sequence. Further, each entry pointincludes a flag (“is_angle_change” flag) that indicates whether an anglechange to the characteristic point is available. Since an angle changeis available at the source packet located at the start of the interleaveunit constituting the multi-angle section, the “is_angle_change” flag inthe entry point indicating the starting source packet of the interleaveunit is always set ON. Also, the entry point indicating the startingsource packet of the interleave unit is associated with In_Time in theplayitem information by the entry point.

The entry map for each ES indicates the source packet numbers of thecharacteristic points for respective stream types in correspondence withthe PTSs. Accordingly, by referencing this entry map, it is possible toobtain, from an arbitrary time point in the ATC sequence, source packetnumbers that indicate locations of the characteristic points for the ESsthat are closest to the arbitrary time point.

This completes the explanation of the clip information file for 2D. Nextis a detailed explanation of the clip information file for 3D. FIG. 49Bshows the internal structure of clip information file for 3D. The clipinformation file for 3D includes: “clip dependent information(dependent-view management information)” which is clip information forthe file dependent; and “clip base information (base-view managementinformation)” which is clip information for the file base, as well asthe “clip information for file 2D” that is regular clip information(management information). The reason is as follows. As described, thestereoscopic interleaved stream file is stored in a directory that isdifferent from the directory in which the regular stream files arestored, to prevent them from mixing each other. Accordingly, the clipinformation files cannot be associated with the stereoscopic interleavedstream file. Thus the clip dependent information and the clip baseinformation are stored in the clip information file for 2D.

The clip dependent information and the clip base information differ fromthe clip information file for 2D in that the clip dependent informationand the clip base information include metadata that has the extent startpoint sequence.

As shown in FIG. 49B, the clip dependent information includes the extentstart point sequence, and the clip base information also includes theextent start point sequence. The characteristic point informationincludes an entry map, and the extension data includes an extensionentry map.

In the 3D output mode, the clip information file is divided into a clipbase information file and a clip dependent information file.

FIG. 49C shows the clip base information file. The clip base informationfile includes clip base information and a basic entry map. The clip baseinformation includes extent start point information.

FIG. 49D shows the clip dependent information file. The clip dependentinformation file includes clip dependent information and an extensionentry map. The clip dependent information includes extent start pointinformation.

A clip information file for the 2D output mode is stored under thedirectory for the clip information file (CLPI directory). The clip baseinformation file is generated from the clip information file in the 3Doutput mode, and is treated to be stored in the clip information filefor the 2D output mode.

A dummy clip information file is stored under the directory for the clipinformation file (CLPI directory). The dummy clip information file isassigned with a file name that is represented by a number correspondingto the file dependent, namely, a number generated by adding “1” to theidentification number of the file 2D/file base. The clip dependentinformation file is generated in the 3D output mode from the clipinformation file corresponding to the file 2D, and is treated to bestored in the dummy clip information file. Suppose here that the clipinformation file in the 2D output mode is 00001.clpi, then the clip baseinformation file in the 3D output mode is treated to be stored in00001.clpi, and the clip dependent information file in the 3D outputmode is treated to be stored in 00002.clpi.

<Extent Start Point>

The following explains the extent start point.

As described above, the stereoscopic interleaved stream file is composedof two clip AV streams (BDAV MPEG2 transport stream). The pair of extentstart point information enables the stereoscopic interleaved stream fileto be divided into two AV streams. The extent start point information issupplied as follows.

(1) An extent start point information table is supplied, to the playbackdevice, in a piece of clip information that is referenced by a playitemof a playlist which includes a sub-path of “sub-path type=8”. It shouldbe noted here that the sub-path of “sub-path type=8” is an out-of-MUXdependent-view video stream playback path of an on-disc type.

(2) Another extent start point information table is supplied, to theplayback device, in a piece of clip information that is referenced by asub-playitem of a playlist which includes a sub-path of “sub-pathtype=8”.

When a flag in the playitem information (flug_is_multiangle_flag), whichindicates whether a multi-angle section exists, is set ON, the extentstart point information tables in a pair are supplied to the playbackdevice, one in a piece of clip information that is referenced by anangle ID value, and the other in a piece of clip information that isreferenced by a sub-clip entry ID value.

The extent start point information in the clip information file has thefollowing data structure. The ID1 value and ID2 value in the extensiondata in ext_data_entry( ) should be set to 0x0002 and 0x0004,respectively.

The clip information file including the extent start point informationtables needs to satisfy the following two conditions.

(a) The clip information file needs to be referenced by a playitem of aplaylist which includes a sub-path of “sub-path type=8”.

(b) The clip information file needs to be referenced by a sub-playitemin a sub-path of “sub-path type=8”. Note that the sub-path of “sub-pathtype=8” is an out-of-MUX dependent-view video stream playback path of anon-disc type.

FIG. 50 shows the correspondence among the clip information file,playlist, and stereoscopic interleaved stream file. On the right side ofFIG. 50, the stereoscopic interleaved stream file is shown, and on theleft side of FIG. 50, the clip information file is shown. In the middleof FIG. 50, the first row shows the file base, the second row shows theclip base information file, the third row shows the 3D playlist, thefourth row shows the clip dependent information file, and the fifth rowshows the file dependent.

The arrows bk1 and bk2 indicate that the file base and the filedependent are obtained respectively by dividing the stream file shown onthe right side of the drawing.

The clip information file shown on the left side of FIG. 50 includescharacteristic point information, extension data, clip base information,and clip dependent information. The arrows bk3 and bk4 indicate that theextent start point information tables in the clip base information andthe clip dependent information enable the stereoscopic interleavedstream file to be divided.

The following explains the extent start point.

In the extent start point information of the clip information file, anID1 value and an ID2 value in the extension data in ext_data_entry( )should be set to 0x0002 and 0x0004, respectively.

The clip information file including the extent start point informationneeds to satisfy the following two conditions.

(i) The clip information file needs to be referenced by a playitem of aplaylist which includes a sub-path having a sub-path type indicating 8.

(ii) The clip information file needs to be referenced by a sub-playitemin a sub-path having a sub-path type indicating 8. Note that thesub-path having a sub-path type indicating 8 is an out-of-MUXdependent-view video stream playback path of an on-disc type.

The stereoscopic interleaved stream file is composed of two clip AVstreams (BDAV MPEG2 transport streams). The pair of extent start pointinformation enables the stereoscopic interleaved stream file to bedivided into two AV streams. The extent start point information issupplied as follows.

(1) An extent start point information table is stored in clipinformation that is referenced by a playitem of a playlist whichincludes a sub-path having a sub-path type indicating 8, so as to besupplied to the playback device.

(2) Another extent start point information table is stored in clipinformation that is referenced by a sub-playitem of a playlist whichincludes a sub-path having a sub-path type indicating 8, so as to besupplied to the playback device.

If the “is_multiangle” flag in the playitem is set to 1, the pair of theextent start point information tables is clip information referred by anangle ID value and clip information referred by a subclip entry IDvalue, respectively, so as to be supplied to the playback device.

FIGS. 51A and 51B show the internal structure of the clip baseinformation and the clip dependent information. As shown in FIG. 51A,the clip base information and the clip dependent information include:“clip stream type information” indicating the stream type to which thecorresponding AV clip belongs; “application type information” indicatingthe type to which the application composed of the corresponding AV clipbelongs, such as a movie application, a time-base slide-showapplication, or a browsable slide-show application; “TS recording rate”indicating a transfer rate at which the TS packets in the AV clip aretransferred in the playback device after the source packets pass throughthe source packet depacketizer; “number of source packets” indicatingthe number of source packets constituting the corresponding AV clip;“ATC delta” indicating a difference in ATC from the ATC sequenceconstituting the preceding AV clip; “extent start point informationtable”; and “extent start point information”.

FIG. 51B shows the internal structure of the extent start pointinformation table. As shown in FIG. 51B, the extent start pointinformation table includes “number_of_extent_start_point”, and as many“SPN_extent_start_point” as the number indicated by the“number_of_extent_start_point”.

The “number_of_extent_start_point” indicates the number of Extents thatbelong to the related AV stream file. The extent start point informationtables in the clip base information and the clip dependent informationin the same pair have the same value in the“number_of_extent_start_point”.

The number of “SPN_extent_start”s (SPN_extent_start[0] throughSPN_extent_start [number_of_extent_start_point]) is“number_of_extent_start_point+1”. Each SPN_extent_start is specified bythe Extent identifier [extent_id], and is a 32-bit value that indicatesa source packet number of the source packet that corresponds to theextent_id^(th) Extent in the AV stream file.

The following explains the extension data of the clip information file.The extension data includes an extension entry map. The extension entrymap, as is the case with the basic entry map, is composed of a pluralityof entry points. More specifically, in each entry point constituting theextension entry map, a source packet number that indicates the locationof the characteristic point in the ATC sequence is associated with a PTSthat indicates the location of the characteristic point in the STCsequence. Each entry point further includes: a flag (“is_angle_change”flag) that indicates whether an angle change to the characteristic pointis available; and information (I_size) that indicates the size of theintra picture located at the start of GOP. The extension entry mapdiffers from the basic entry map in that the following restrictions areimposed thereon.

When the extension entry map includes entries for the MPEG4-MVC viewcomponents, the extension entry map should also include entries for viewcomponents in correspondence with the PTSs in the extension entry map.

When there are two clip information files whose respective applicationtypes are “1” and “8” and which correspond to a stereoscopic interleavedstream file, the following conditions should be satisfied. That is tosay, when an Extent identified by an Extent ID value of clip informationwith “application type=1” (clip information of an application type forthe primary video stream) includes a source packet that is to bereferenced by PTS_EP_Start of the base-view video stream, an Extentidentified by the same Extent ID value of clip information with“application type=8” should include a source packet that is to bereferenced by the same PTS_EP_Start_value of the dependent-view videostream.

FIG. 52 shows the basic entry map and the extension entry map. In FIG.52, the fifth row shows a plurality of pairs of a dependent-view datablock and a base-view data block. The fourth row shows a sequence ofsource packets that constitute the dependent-view data blocks and thebase-view data blocks. The first row shows the view components that areidentified by the PTSs. The second row shows the basic entry map. Thethird row shows the extension entry map.

When Extent[1] specified by the extent start point with “Extent ID=1”has a source packet [n1] with “SPN=n1” that is referenced by an entrywith “PTS_EP_Start=t1” of the base-view video stream, Extent[1]specified by the extent start point with “Extent ID=1”, which is thesame Extent ID of the clip information with “application type=8”,includes a source packet [n11] with “SPN=n11” that is referenced by anentry with “PTS_EP_Start=t1”, which is an entry having the same value inthe dependent-view video stream.

As apparent from this, when a source packet located at the start ofGOP(i) of the base-view video stream and a source packet located at thestart of GOP(i) of the dependent-view video stream belong to the sameinterleave Extent unit, entries pointing to the source packet located atthe start of GOP(i) of the base-view video stream and the source packetlocated at the start of GOP(i) of the dependent-view video stream areadded into each of the basic entry map and the extension entry map.Accordingly, by using both the basic entry map and the extension entrymap, it is possible to ensure the continuous reading of the GOP(i) ofthe base-view video stream and the GOP(i) of the dependent-view videostream.

FIG. 53 shows entries that are not permitted in the extension entry map.

It is presumed here that a source packet [x] with “SPN=x” that isreferenced by an entry with “PTS_EP_Start=x” of the base-view videostream exists at the start of a file base Extent that is referenced byan Extent ID=x, and that a source packet [y] with “SPN=y” that isreferenced by an entry with “PTS_EP_Start=x” exists at the start of afile dependent Extent that is referenced by an Extent ID=j, wherein “i”and “j” are different from each other.

It cannot be said that Extent [i] specified by the extent start point ofthe clip dependent with “Extent ID=i” includes a source packet with“SPN=x” that is referenced by an entry with “PTS_EP_Start=x”, which isan entry of the base-view video stream having the same value. Thereforean entry with “PTS_EP_Start=x” cannot be added into the extension entrymap.

When a source packet located at the start of GOP(i) of the base-viewvideo stream and a source packet located at the start of GOP(i) of thedependent-view video stream belong to different interleave Extent units,an entry pointing to the source packet located at the start of GOP(i) isnot added into any of the basic entry map and the extension entry map.In this case, GOP(i) of the base-view video stream and GOP(i) of thedependent-view video stream are excluded from the access destination ofthe random access. This prevents the access performance from beingdegraded.

FIG. 54 is a flow chart showing the playitem playback procedure.

In step S201, it is judged whether or not the current output mode is the3D output mode. When the current output mode is the 2D output mode, aloop constituted from steps S203 through S206 is performed.

In step S203, the stream file, which is identified by: “xxxxx” describedin Clip_information_file_name of the current playitem; and extension“m2ts”, is opened. In step S204, the “In_time” and “Out_time” of thecurrent playitem are converted into “Start_SPN[i]” and “End_SPN[i]” byusing the entry map corresponding to the packet ID of the video stream.

In step S205, the Extents belonging to the reading range [i] areidentified to read the TS packet with PID [i] from the Start_SPN[i] tothe End_SPN[i]. In step S206, the drive of the recording medium isinstructed to continuously read the Extents belonging to the readingrange [i].

When the current output mode is the stereoscopic output mode, a loopconstituted from steps S300 through S308 is performed.

In step S300, the stream file, which is identified by: “xxxxx” describedin the Clip_information_file_name of the current playitem; and extension“ssif”, is opened. In step S301, the base-view video stream is assignedto either the left-view or right-view video plane in accordance with thebase-view indicator of the current playitem information, and thedependent-view video stream is assigned to the other, namely theleft-view or right-view video plane that has not been assigned to thebase-view video stream.

In step S302, the “In_time” and “Out_time” of the current playitem areconverted to “Start_SPN[i]” and “End_SPN[i]” by using the basic entrymap corresponding to the base-view video stream.

In step S303, the sub-playitem corresponding to the dependent-viewstream is identified. In step S304, the “In_time” and “Out_time” of theidentified sub-playitem are converted into “Start_SPN[j]” and“End_SPN[j]” by using the extension entry map corresponding to thedependent-view video stream.

The Extents belonging to the reading range [i] are identified to readthe TS packet having the packet ID [i] constituting the base-view videostream from “Start_SPN[i]” to “End_SPN[i]” (step S305). The Extentsbelonging to the reading range [j] are identified to read the TS packethaving the packet ID [j] from “Start_SPN[j]” to “End_SPN[j]” (stepS306). Following this, in step S307, the Extents belonging to thereading ranges [i] and [j] are sorted in the ascending order. In stepS308, the drive is instructed to continuously read the Extents belongingto the reading ranges [i] and [j] using the sorted addresses. Afterthis, when the source packet sequence is read, in step S309, thebase-view and dependent-view ATC sequences are restored and supplied tothe PID filters for the base view and dependent view.

As described above, according to the present embodiment, when GOPs ofthe main TS and sub-TS are to be recorded onto the above-describedrecording medium, entries of the extension entry map point to onlydependent-view picture data pieces that correspond to base-view picturedata pieces pointed to by entries of the basic entry map as those thatare to be played back at the same playback times as the dependent-viewpicture data pieces.

The picture data pieces pointed to by entries of the basic entry map andthe picture data pieces pointed to by entries of the extension entry mapmake pairs in Extents. Accordingly, when an Extent is accessed via thebasic entry map and the extension entry map, it is possible to play backeach set of GOPs of the base view and dependent view corresponding toeach other as one unit. This makes it possible to solve the problem ofplayback start delay.

Note that it may be possible to define that each extent include at leastone entry point, as shown in FIG. 88A. With this definition, it ispossible to prevent increase in length of an interval between entrypoints, thereby suppressing a delay amount for jump playback or the likeas shown in FIG. 88B.

Embodiment 4

The present embodiment relates to an improvement for restoring the ATCsequence from the data blocks that constitute the stereoscopicinterleaved stream file. FIG. 55 shows how the ATC sequence is restoredfrom the data blocks constituting the stereoscopic interleaved streamfile.

The fourth row of FIG. 55 shows a plurality of data blocks thatconstitute the stereoscopic interleaved stream file. The third row showsthe source packet sequence multiplexed in the main TS and the sub-TS.

The second row shows a set of STC sequence 2 constituting the dependentview, an entry map, and ATC sequence 2 constituting the dependent view.The first row shows a set of STC sequence 1 constituting the dependentview, an entry map, and ATC sequence 1 constituting the dependent view.The arrows extending from the third row to the first and the second rowsschematically show that the ATC sequences 1 and 2 are restored from thedata blocks of the two TSs (main TS and sub-TS) interleaved in thestereoscopic interleaved stream file. These ATC sequences are associatedwith the STC sequences by the entry map in the clip information.

This completes the description of the recording medium in the presentembodiment. In the following, the playback device will be described indetail.

The playback device in the present embodiment has a structure in whichthe reading unit receives inputs of source packets from two recordingmediums. For this purpose, the reading unit includes two drives and tworead buffers. The two drives are used to access the two recordingmediums, respectively. The two read buffers are used to temporarilystore the source packets input from the two drives and output them tothe decoder. An ATC sequence restoring unit is provided between the twodrives and the two read buffers. The ATC sequence restoring unitseparates the ATC sequence constituting the base-view stream and the ATCsequence constituting the dependent-view stream, from the source packetsin the interleaved stream file read from one recording medium, andwrites the two ATC sequences into the two read buffers, respectively.With this structure, the playback device can process the ATC sequenceconstituting the base-view video stream and the ATC sequenceconstituting the dependent-view video stream as if they have been readfrom different recording mediums, respectively.

FIGS. 56A and 56B show how the ATC sequence is restored. FIG. 56A showsthe internal structure of the reading unit provided with the ATCsequence restoring unit. As described above, the ATC sequence restoringunit is provided between the two drives and the two read buffers. Thearrow B0 symbolically indicates the input of the source packet from onedrive. The arrow B1 schematically indicates the writing of the ATCsequence 1 constituting the base-view video stream. The arrow D1schematically indicates the writing of the ATC sequence 2 constitutingthe dependent-view video stream.

FIG. 56B shows how the two ATC sequences obtained by the ATC sequencerestoring unit are treated. In the middle part of FIG. 56B, the PIDfilters provided in the demultiplexing unit are shown. On the left sidein the figure, the two ATC sequences obtained by the ATC sequencerestoring unit are shown. The right side of the figure shows thebase-view video stream, dependent-view video stream, left-eye PG stream,right-eye PG stream, base-view IG stream, and dependent-view IG stream,which are obtained by demultiplexing the two ATC sequences.

FIGS. 57A through 57D show one example of the extent start pointinformation table in the base-view clip information and one example ofthe extent start point information table in the dependent-view clipinformation. FIG. 57A shows the extent start point information table inthe base-view clip information and the extent start point informationtable in the dependent-view clip information.

FIG. 57B shows base-view data blocks B[0], B[1], B[2], . . . B[n]constituting the ATC sequence 1, and dependent-view data blocks D[0],D[1], D[2], . . . D[n] constituting the ATC sequence 2. FIG. 57C showsthe number of source packets in the dependent-view data block and thenumber of source packets in the base-view data block.

FIG. 57D shows a plurality of data blocks included in the stereoscopicinterleaved stream file.

As shown in FIG. 57B, when the ATC sequence 2 is composed of thedependent-view data blocks D[0], D[1], D[2], . . . D[n], the sourcepacket numbers 0, b1, b2, b3, b4, . . . bn, which are relative to thedependent-view data blocks D[0], D[1], D[2], . . . D[n] constituting theATC sequence 2, are written in the SPN_extent_start in the extent startpoint information table of the file dependent.

When the ATC sequence 1 is composed of the base-view data blocks B[0],B[1], B[2], . . . B[n], the number of source packets 0, a1, a2, a3, a4,. . . an, which are relative to the base-view data blocks B[0], B[1],B[2], . . . B[n] constituting the ATC sequence 1, are written in theSPN_extent_start in the extent start point information table of the filebase.

FIG. 57C shows the number of source packets in an arbitrarydependent-view data block D[x] and the number of source packets in anarbitrary base-view data block B[x]. When the starting source packetnumber of the dependent-view data block D[x] is bx and the startingsource packet number of the dependent-view data block D[x+1] is bx+1,the number of source packets constituting the dependent-view data blockD[x] is “(bx+1)−bx”.

Similarly, when the starting source packet number of the base-view datablock B[x] is ax and the starting source packet number of the base-viewdata block B[x+1] is ax+1, the number of source packets constituting thebase-view data block B[x] is “(ax+1)−ax”.

When the starting source packet number of the last base-view data blockB[n] in the stereoscopic interleaved stream file is “an” and the numberof source packets constituting the ATC sequence 1 is“number_of_source_packet1”, the number of source packets constitutingthe base-view data block B[n] is “number_of_source_packet1-an”.

When the starting source packet number of the last dependent-view datablock D[n] in the stereoscopic interleaved stream file is “bn” and thenumber of source packets constituting the ATC sequence 2 is“number_of_source_packet2”, the number of source packets constitutingthe dependent-view data block D[n] is “number_of_source_packet2-bn”.

FIG. 57D shows the starting source packet numbers of the dependent-viewdata blocks and the base-view data blocks in the present example.

In the stereoscopic interleaved stream file, the starting SPN of D[0] is“0” and the starting SPN of B[0] is “b1”.

The starting SPN of D[1] is “b1+a1”, representing the sum of b1 (thenumber of source packets in the preceding dependent-view data blockD[0]) and a1 (the number of source packets in the preceding base-viewdata block B[0]).

The starting SPN of B[1] is “b2+a1” (=b1+a1+b2−b1), representing the sumof b1 (the number of source packets in the preceding dependent-view datablock D[0]) and a1 (the number of source packets in the precedingbase-view data block B[0]) and “b2−b1” (the number of source packets inthe preceding dependent-view data block D[1]).

The starting SPN of D[2] is “b2+a2” (=b1+a1+b2−b1+a2−a1), representingthe sum of b1 (the number of source packets in the precedingdependent-view data block D[0]) and a1 (the number of source packets inthe preceding base-view data block B[0]) and “b2−b1” (the number ofsource packets in the preceding dependent-view data block D[1]) and“a2−a1” (the number of source packets in the preceding base-view datablock B[1]).

The starting SPN of B[2] is “b3+a2” (=b1+a1+b2−b1+a2−a1+b3−b2),representing the sum of b1 (the number of source packets in thepreceding dependent-view data block D[0]) and a1 (the number of sourcepackets in the preceding base-view data block B[0]) and “b2−b1” (thenumber of source packets in the preceding dependent-view data blockD[1]) and “a2−a1” (the number of source packets in the precedingbase-view data block B[1]) and “b3−b2” (the number of source packets inthe preceding dependent-view data block D[2]).

FIGS. 58A through 58C are illustrations provided for explanation of thesource packet numbers of arbitrary data blocks in ATC sequences 1 and 2.

Suppose that an attempt is made to obtain a source packet number in astereoscopic interleaved stream file in D[x] with a source packet number“bx”, in the ATC sequence 2 shown in FIG. 58A. n this case, the startingsource packet number of D[x] is “bx+ax”, representing the sum of sourcepacket numbers which are relative to data blocks D[0], B[0], D[1], B[1],D[2], B[2], . . . D[x−1], B[x−1], as shown in FIG. 58B.

Suppose that an attempt is made to obtain a source packet number in astereoscopic interleaved stream file in B[x] with a source packet number“ax”, in the ATC sequence 1 shown in FIG. 58A. In this case, thestarting source packet number of B[x] is “bx+1+ax”, representing the sumof source packet numbers which are relative to data blocks D[0], B[0],D[1], B[1], D[2], B[2], . . . D[x−1], B[x−1], D[x], as shown in FIG.58B.

FIG. 58C shows a file base and a file dependent, wherein the Extentsconstituting the file base are the above-described base-view data blocksand the Extents constituting the file dependent are the above-describeddependent-view data blocks.

The starting LBN and continuous length of EXT1[x] and EXT2[x] areobtained as follows, wherein EXT1[x] is an Extent of a file basecorresponding to B[x], and EXT2[x] is an Extent of a file dependentcorresponding to D[x].

The LBN can be obtained from the starting source packet number of D[x]by converting the source packet into the LBN by performing a calculation((bx+ax)*192/2048). Similarly, the LBN can be obtained from the startingsource packet number of B[x] by converting the source packet into theLBN by performing a calculation ((bx+1+ax)*192/2048). Here, the number“192” indicates the number of bytes representing the source packet size,and the number “2048” indicates the number of bytes representing thesector size (logical block size). The LBN of an Extent in thestereoscopic interleaved stream file that is closest to these LBNs canbe obtained by using these converted LBNs as “file_offset” that is anargument of a function “SSIF_LBN(file_offset)”. The function SSIF_LBN isa function that returns an LBN corresponding to the file_offset aftertracing the allocation descriptors of the SSIF starting with thefile_offset.

Accordingly, the starting LBN of EXT2[x] is represented as “SSIF_LBN((bx+ax)*192/2048)”. Also, the starting LBN of EXT1[x] is represented as“SSIF_LBN ((bx+1+ax)*192/2048)”.

On the other hand, the continuous length of EXT2[x] is represented as“SSIF_LBN ((bx+1+ax)*192/2048)−SSIF_LBN ((bx+ax)*192/2048)”. Also, thecontinuous length of EXT1[x] is represented as “SSIF_LBN((bx+1+ax+1)*192/2048)−SSIF_LBN((bx+1+ax)*192/2048)”. When file entriesindicating these starting LBNs and continuous lengths are generated on amemory, it is possible to obtain file bases and file dependentsvirtually.

The demultiplexing performed by the two ATC sequences is based on thebasic stream selection table and the extension stream selection tabledescribed in Embodiment 1. The ATC sequence restoring unit is realizedby creating a program that causes the hardware resource to perform theprocess shown in FIG. 59. FIG. 59 shows the procedure for restoring theATC sequence.

In step S91, the ATC sequence for base-view is set as the ATC sequence1, and the ATC sequence for dependent-view is set as the ATC sequence 2.In step S92, the variable “x” is initialized to “1”. The variable “x”specifies a base-view data block and a dependent-view data block. Afterthis, the control enters a loop in which steps S94 through S96 arerepeatedly performed as follows.

It is judged whether or not a source packet number bx specified by thevariable “x” is equal to a source packet number bn specified by the lastnumeral “n” of the base-view data block (step S93). When the result ofthe judgment is in the negative (No in step S93), the source packetsfrom the source packet (bx+ax), which is specified by the source packetnumber “bx+ax”, to the source packet immediately before the sourcepacket (b_(x+1)+ax) specified by the source packet number “b_(x+1)+ax”are added into the ATC sequence 2 (step S94). Then, the source packetsfrom the source packet (bx+1+ax) to the source packet immediately beforethe source packet (bx+1+ax+1) are added into the ATC sequence 1 (stepS95). And then the variable “x” in incremented (step S96). These stepsare repeated until it is judged Yes in step S93.

When it is judged Yes in step S93, as many source packets as the numberspecified by “number_of_sourcepacket2-bn” starting from the sourcepacket number “bn” are added into the ATC sequence 2 (step S97). And asmany source packets as the number specified by“number_of_source_packet1-bn” starting from the source packet number“an” are added into the ATC sequence 1 (step S98).

After the ATC sequences 1 and 2 are restored through the above-describedsteps, the file base is virtually opened by generating, in the memory,the file entry that indicates the start LBN of the base-view data blockand the continuation length (step S99). Similarly, the file dependent isvirtually opened by generating, in the memory, the file entry thatindicates the start LBN of the dependent-view data block and thecontinuation length (step S100).

<Technical Meaning of Opening File Base>

When a random access from an arbitrary time point is to be performed, asector search within a stream file needs to be performed. The sectorsearch is a process for identifying a source packet number of a sourcepacket corresponding to the arbitrary time point, and reading a filefrom a sector that contains a source packet of the source packet number.

Since the size of one Extent constituting the stereoscopic interleavedstream file is large, the sector search requires a wide range ofsearching. In that case, when a random access from an arbitrary timepoint is performed, it may take a long time to identify thereading-target sector.

This is because, in the interleaved stream file, data blocksconstituting the base-view video stream and the dependent-view videostream are disposed in the interleaved manner to constitute one longExtent, and the allocation descriptor of the file entry of theinterleaved stream file merely indicates the start address of the longExtent.

In contrast, the file base is composed of a plurality of short Extents,and the start address of each Extent is written in the allocationdescriptor. As a result, the sector search requires a narrow range ofsearching. Thus, when a random access from an arbitrary time point isperformed, the reading-target sector can be identified in a short time.

That is to say, since the data blocks constituting the base-view videostream are managed as Extents of the file base, and the start address ofthe data block is written in the allocation descriptor in the file entrycorresponding to the file base, it is possible to quickly reach thesector including the source packet at the target random access position,by starting the sector search from the start address of the Extent thatcontains the target random access position.

With the above-described structure in which the data blocks constitutingthe base-view video stream are managed as Extents of the file base, andthe start address of each Extent and the continuation length are writtenin the allocation descriptor in the file entry corresponding to the filebase, it is possible to perform a random access from an arbitrary timepoint in the base-view video stream at a high speed.

More specifically, the sector search is performed as follows. First, theentry map corresponding to the base-view video stream is used to detecta source packet number that is the random access position correspondingto the arbitrary time point.

Next, the extent start point information in the clip informationcorresponding to the base-view video stream is used to detect an Extentthat contains the source packet number that is the random accessposition.

Further, the allocation descriptor in the file entry corresponding tothe file base is referenced to identify the start sector address of theExtent that contains the source packet number that is the random accessposition. Then a file read is performed by setting a file pointer to thestart sector address, and a packet analysis is executed onto the readsource packet to identify the source packet with the source packetnumber that is the random access position. Then the identified sourcepacket is read. With this procedure, the random access to the main TS isexecuted efficiently. This also applies to the sub-TS.

As described above, according to the present embodiment, Extents of thebase-view video stream and the dependent-view video stream in theinterleaved stream file are supplied to the demultiplexing unit and thedecoder after they are rearranged based on the extent start pointinformation. Thus the decoder and program can treat, as the filesvirtually existing on the recording medium, the file base storing thebase-view video stream and the file dependent storing the dependent-viewvideo stream.

In this structure, the base-view video stream and the dependent-viewvideo stream for the stereoscopic viewing are recorded on the recordingmedium, while the base-view video stream and the dependent-view videostream can be accessed separately. With this structure, the processingefficiency of the playback device is improved.

Embodiment 5

In the present embodiment, the following describes a problem of HDMIoutput, a super-resolution method, and a method of increasing frame ratein order to play back 3D contents stored in a BD-ROM.

(HDMI Output)

Firstly, identification of 3D display/glasses method is described withreference to FIG. 60. In the case where a plurality of TVs are connectedwith a 3D displayable player, it is desirable to notify the player, viaan I/F such as HDMI, of whether glasses are necessary for 3D viewingwith use of each TV, and if necessary, which type of glasses arenecessary. For example, if it is recognizable in a BD player that activeshutter glasses are necessary for 3D viewing with use of a TV connectedwith the BD player, it is possible to program such that before 3Dplayback is started, a viewer is informed of a message that indicatesactive shutter glasses are necessary for 3D viewing with use of theconnected TV. Accordingly, it is desirable that apparatuses connectedwith the BD player via E-EDID, InfoFrame, or the like share informationfor identifying whether glasses are necessary for 3D viewing with use ofeach TV, and if necessary, which type of glasses are necessary(anaglyph, circular deflection, or active shutter, for example), suchthat the BD player is informed of the information. If a communicationfunction between each TV and the glasses is prepared, it is possible toappropriately change 3D videos for each user by providing the playerwith position information of the glasses (specifically, the verticalline extending from the center of the TV screen and thehorizontal/vertical angle of the glasses). In the case where a TV-1 is a2D dedicated TV and a TV-2 is a 3D dedicated TV, it is desirable, asoutput for the TV-1, to extract and output only a right eye video or aleft-eye video to be output to the TV-2, or display a message indicatingthat 3D viewing is impossible in the TV-1 such as a message “3D is beingplayed back in TV-2” or a message “3D viewing is impossible in TV-1”. Asshown in FIG. 61, in the case where a playback video is switched to a 2Dvideo to a 3D video, it is desirable to doubly output only one of aright-eye video and a left-eye video at a 3D video frame rate with nochange. This is because change of the frame rate causes delay due to thenecessity of authentication of HDMI, for example. However, in the casewhere a 3D video is displayed, in consideration of that glasses darkenthe user's eyesight, a video to be displayed in a TV has a highbrightness level, and appropriate processing for performing 2D videodisplay might not be performed on the video. In view of this, in thecase where only one of a right-eye video and a left-eye video is doublyoutput like a section “2D dubbing playback” shown in FIG. 61, when avideo is output via HDMI, a flag indicating that playback. Accordingly,it is possible to judge, in the TV, a video to be transferred is a 2Dvideo. This enables control such as image processing appropriate for 2Dvideo playback. Next, the correlation between subtitles and menu streamsused for BD is described with reference to FIG. 62. Suppose that aplayer needs to simultaneously perform 2D output and 3D output. Sincepresentation Graphics (a stream for subtitle, and is abbreviated as“PG”) and Interactive Graphics stream (a stream for menu, and isabbreviated as “IG”) that are used in BD-ROMs are displayed as differentpatterns, PG and IG each have a different PID and accordingly need to bedecoded separately. However, in order to prevent occurrence of thedifference between the user's operation while viewing 2D display on a TVand the viewer's operation while viewing 3D viewing on the TV, it isdesirable that all pieces of information of 2D stream (C) correspond toall pieces of information of 3D left-eye/right-eye streams (L,R), exceptall patterns of 2D stream (C) and display positions thereof and allpatterns of 3D left-eye/right-eye streams (L,R) and display positionsthereof. For example, with respect to PG, it is desirable that streamsare recorded such that the same subtitle is displayed at the samedisplay time among C, L, and R (that is, only patterns of subtitle anddisplay information are different among C, L, and R). Also, with respectto IG, it is desirable that streams are recorded such that the pagestructure of a menu, the shift among buttons, button commands inexecution, and the like are the same among corresponding C, L, and R(that is, only patterns of subtitle and display information aredifferent among C, L, and R), thereby to realize the same menu operationamong C, L, and R. This is necessary to realize that a 2D viewer and a3D viewer can the same subtitle and menu in the TV-1 and the TV-2,respectively, and menu can be controlled by both the TV-1 and the TV-2.n order to perform simultaneous output, the player separately overlaysL, R, and C to generate 2D video and 3D video, as shown in FIG. 62.Although only an IG decoder is shown in FIG. 62, the same applies to aPG decoder. Also, instead of using an L video for 3D for 2D videooutput, R video may be used.

(Super-Resolution)

Next, processing for realizing more smooth 2D/3D video display isdescribed, with reference to FIG. 63. In a TV that performs 2D displaybased on the input in which a left-eye (Ln) video and a right eye (Rn)video alternately succeed, such as L1, R1, L2, R2, . . . , eitherleft-eye videos or right-eye videos are displayed, such as L1, L2, L3, .. . or R1, R2, R3, . . . Accordingly, in the case where a right-eyevideo and a left-eye video are simultaneously filmed according to aconventional art, only the image quality of the video L2 is increasedusing a video (L1) temporally previous to the video L2 and a video (L3)temporally subsequent to the video L2. However, there is a case that aL2 video is more highly associated with R1, R2, and R3 videos for theeye on the other side than L1 and L3 videos. Accordingly, even in thecase where 2D display is performed, it is possible to further increasethe image quality by referring to a video that is not displayed. Themethod of increasing the image quality is no object here. It is greatlyimportant to use either a right-eye video or a left-eye video that isnot displayed (both of the right-eye video and the left-eye video afterall) in processing of increasing the image quality while performing 2Ddisplay, in order to increase the image quality with a high precision.In this case, although 2D display is performed for the viewer, theplayer and the TV need to be connected with each other such that 3Ddisplay is performed. It is necessary to perform connectionauthentication as 3D with respect to I/F such as HDMI to perform switchcontrol to cause the player to output both of L/R videos. In the case ofa TV performing 3D display based on left-eye videos (Ln) and right-eyevideos (Rn) such as L1, R1, L2, R2, . . . that are sequentially input,it is considered to be effective to use both of L/R videos is effectivein order to increase the image quality of each of the videos. Also, itis possible to estimate, with a high accuracy, a frame to be used forperforming increasing the image quality by recording the opticalparameter of the L/R camera (angle between cameras, the focal distance,or the like) in a stream.

(Increase in Frame Rate)

Next, the following describes processing for realizing more smooth 2D/3Dvideo display, with reference to FIG. 63 again. Especially, when 3Ddisplay is realized, right-eye videos and left-eye videos are oftenalternately displayed in accordance with the time division displaymethod. This tends to cause the user to suffer from eye strain due tothe low frame rate for display. Furthermore, in the case where there isa great change amount of video materials among frames due to the recentincrease in the screen size of TV, the user tends to feel tired due tothe low frame rate. Accordingly, in the case where 3D playback isperformed, playback is normally performed at a frame rate such as aframe rate twice or three times the normal frame rate of a videomaterial. However, even if display is performed at a two or three timesfaster than normal, a video being displayed is the same as the videobeing displayed at the normal speed. This still remains a problem causedby a change amount of videos among frames in viewing by a large screen.For example, in the case where display is performed at twice faster thannormal, left-eye videos and right-eye videos are displayed two sets foreach time such as L1, R1, L1, R1, L2, R2, L2, R2, . . . At the seconddisplay of L1,R1, it is possible to reduce the user's tired feeling bydisplaying videos (an intermediate video of L1 and L2 and anintermediate video of R1 and R2) whose time resolutions have beenincreased using a high image quality circuit. In other words, it ispossible to reduce the user's eye strain in 3D viewing by a large screenby generating an intermediate vide at a sampling frequency higher than asampling frequency (frame rate) of a video material and performing 3Ddisplay.

Note that in the case of a TV that performs stereoscopic display bydisplaying parallax images for the left eye and right eye in which aviewer needs to wear glasses, when parallax images for the left eye andright eye become larger than a distance between the right eye and theleft eye of the viewer, a picture as 3D is not composed. This causes aproblem that the user suffers from eye strain and 3D sickness.Accordingly, as a TV display processing, it is desirable to shift theright videos and the left videos as a whole to the right or the left fordisplay, such that parallax images for the left eye and right eye arenot misaligned beyond a distance between a right eye and a left eyecorresponding to the smallest glasses among commercially available ones.The player may shift the right videos and the left videos as a whole tothe right or the left to perform output processing, such that anappropriate parallax difference is displayed by causing the viewer toinput or select his age or desired 3D strength on an interactive menuscreen of the BD.

Embodiment 6

The present embodiment describes the production of the recording mediumsdescribed in the embodiments so far, namely, the production act of therecording medium.

The recording method of the present embodiment can be realized as areal-time recording in which AV files (stream files) and non-AV files(files other than the stream files) are generated in real time, and arewritten directly into the AV data recording region and the non-AV datarecording region provided in the recording medium. However, not limitedto this, the recording method of the present embodiment can be realizedas a pre-format recording in which bit streams to be recorded into thevolume region are generated in advance, a master disc is generated basedon the bit streams, and the master disc is pressed, thereby makingpossible a mass production of the optical disc. The recording method ofthe present embodiment is applicable to either the real-time recordingor the pre-format recording.

When the recording method is to be realized by the real-time recordingtechnology, the recording device for performing the recording methodcreates an AV clip in real time, and stores the AV clip into the BD-RE,BD-R, hard disk, or semiconductor memory card.

In this case, the AV clip may be a transport stream that is obtained asthe recording device encodes an analog input signal in real time, or atransport stream that is obtained as the recording device partializes adigital input transport stream. The recording device for performing thereal-time recording includes: a video encoder for obtaining a videostream by encoding a video signal; an audio encoder for obtaining anaudio stream by encoding an audio signal; a multiplexor for obtaining adigital stream in the MPEG2-TS format by multiplexing the video stream,audio stream and the like; and a source packetizer for converting TSpackets constituting the digital stream in the MPEG2-TS format intosource packets. The recording device stores an MPEG2 digital streamhaving been converted into the source packet format, into an AV clipfile, and writes the AV clip file into the BD-RE, BD-R, or the like.When the digital stream is written, the control unit of the recordingdevice performs a process of generating the clip information and theplaylist information in the memory. More specifically, when the userrequests a recording process, the control unit creates an AV clip fileand an AV clip information file in the BD-RE or the BD-R.

After this, when the starting position of GOP in the video stream isdetected from the transport stream which is input from outside thedevice, or when the GOP of the video stream is created by the encoder,the control unit of the recording device obtains (i) the PTS of theintra picture that is positioned at the start of the GOP and (ii) thepacket number of the source packet that stores the starting portion ofthe GOP, and additionally writes the pair of the PTS and the packetnumber into the entry map of the clip information file, as a pair ofEP_PTS entry and EP_SPN entry. After this, each time a GOP is generated,a pair of EP_PTS entry and EP_SPN entry is written additionally into theentry map of the clip information file. In so doing, when the startingportion of a GOP is an IDR picture, an “is_angle_change” flag havingbeen set to “ON” is added to a pair of EP_PTS entry and EP_SPN entry.Also, when the starting portion of a GOP is not an IDR picture, an“is_angle_change” flag having been set to “OFF” is added to a pair ofEP_PTS entry and EP_SPN entry.

Further, the attribute information of a stream in the clip informationfile is set in accordance with the attribute of the stream to berecorded. After the clip and the clip information are generated andwritten into the BD-RE or the BD-R, the playlist information definingthe playback path via the basic entry map in the clip information isgenerated and written into the BD-RE or the BD-R. When this process isexecuted with the real-time recording technology, a hierarchicalstructure composed of the AV clip, clip information, and playlistinformation is obtained in the BD-RE or the BD-R.

This completes the description of the recording device for performingthe recording method by the real-time recording. Next is a descriptionof the recording device for performing the recording method by thepre-format recording.

The recording method by the pre-format recording is realized as amanufacturing method of an optical disc including an authoringprocedure.

FIGS. 64A and 64B show a recording method of an optical disc. FIG. 64Ais a flow chart of the recording method by the pre-format recording andshows the procedure of the optical disc manufacturing method. Theoptical disc manufacturing method includes the authoring step, signingstep, medium key obtaining step, medium key encrypting step, physicalformat step, identifier embedding step, a mastering step, andreplication step.

In the authoring step S201, a bit stream representing the whole volumeregion of the optical disc is generated.

In the signing step S202, a request for signature is made to the AACS LAto manufacture the optical disc. More specifically, a portion isextracted from the bit stream is sent to the AACS LA. Note that the AACSLA is an organization for managing the license of the copyrighted workprotection technologies for the next-generation digital householdelectric appliances. The authoring sites and mastering sites arelicensed by the AACS LA, where the authoring sites perform authoring ofoptical discs by using authoring devices, and the mastering sitesexecute mastering by using mastering devices. The AACS LA also managesthe medium keys and invalidation information. The AACS LA signs andreturns the portion of the bit stream.

In the medium key obtaining step S203, a medium key is obtained from theAACS LA. The medium key provided from the AACS LA is not fixed. Themedium key is updated to a new one when the number of manufacturedoptical discs reaches a certain number. The update of the medium keymakes it possible to exclude certain makers or devices, and toinvalidate an encryption key by using the invalidation information evenif the encryption key is cracked.

In the medium key encrypting step S204, a key used for encrypting a bitstream is encrypted by using the medium key obtained in the medium keyobtaining step.

In the physical format step S205, the physical formatting of the bitstream is performed.

In the identifier embedding step S206, an identifier, which is uniqueand cannot be detected by ordinary devices, is embedded, as electronicwatermark, into the bit stream to be recorded on the optical disc. Thisprevents mass production of pirated copies by unauthorized mastering.

In the mastering step S207, a master disc of the optical disc isgenerated. First, a photoresist layer is formed on the glass substrate,a laser beam is radiated onto the photoresist layer in correspondencewith desired grooves or pits, and then the photoresist layer issubjected to the exposure process and the developing process. Thegrooves or pits represent values of the bits constituting the bit streamthat has been subjected to the eight-to-sixteen modulation. After this,the master disc of the optical disc is generated based on thephotoresist whose surface has been made uneven by the laser cutting incorrespondence with the grooves or pits.

In the replication step S208, copies of the optical disc are produced bya mass production by using the master disc of the optical disc.

FIG. 64B shows the procedure of the recording method by the pre-formatrecording when a general user records any of the various files describedin the embodiment so far onto a recording medium such as BD-R or BD-REby using a personal computer, not when the optical disc ismass-produced. Compared with FIG. 64A, in the recording method shown inFIG. 64B, the physical format step S205 and the mastering step S207 havebeen omitted, and each file writing step S209 has been added.

Next, the authoring step is explained.

FIG. 65 is a flow chart showing the procedure of the authoring step.

In step S101, the reel sets of the main TS and sub-TS are defined. A“reel” is a file which stores the material data of an elementary stream.In the authoring system, the reels exist on a drive on a local network.The reels are data representing, for example, L and R images shot by a3D camera, audio recorded at the shooting, audio recorded after theshooting, subtitles for each language, and menus. A “reel set” is agroup of links to the material files, representing a set of elementarystreams to be multiplexed into one transport stream. In this example, areel set is defined for each of the main TS and the sub-TS.

In step S102, the prototypes of playitem and sub-playitem are defined,and the prototypes of the main path and sub-path are defined by defininga playback order of playitem and sub-playitem. The prototype of theplayitem can be defined by receiving, via a GUI, a specification of areel that is permitted to be played back by a targeted playitem in themonoscopic output mode, and a specification of In_Time and Out_Time. Theprototype of the sub-playitem can be defined by receiving, via a GUI, aspecification of a reel that is permitted to be played back by aplayitem corresponding to a targeted sub-playitem in the stereoscopicoutput mode, and a specification of In_Time and Out_Time.

For the specification of a reel to be permitted to be played back, a GUIis provided to make it possible to check a check box corresponding to,among the links to the material files in the reel set, a link to amaterial file permitted to be played back. With this GUI, numeral inputcolumns are displayed in correspondence with the reels. With use of thenumeral input columns, the priority of each reel is received, and basedon this, the priorities of the reels are determined. With the setting ofthe reels permitted to be played back and the setting of the priorities,the stream selection table and the extension stream selection table aregenerated.

The specification of In_Time and Out_Time is performed when therecording device executes the process in which the time axis of thebase-view video stream or the dependent-view video stream is displayedas a graphic on the GUI, a slide bar is moved on the graphic of the timeaxis, and specification of a positional setting of the slide bar isreceived from the user.

The definition of the playback order of the playitem and thesub-playitem is realized by the following process: a picture at In_Timeof the playitem is displayed as a thumbnail on the GUI, and therecording device receives from the user an operation made onto thethumbnail to set the playback order.

In step S103, a plurality of elementary streams are obtained by encodingthe material files specified by the reel sets. The plurality ofelementary streams include the base-view video stream and thedependent-view video stream, and the audio stream, PG stream, and IGstream that are to be multiplexed with the base-view video stream andthe dependent-view video stream.

In step S104, one main TS is obtained by multiplexing thereinto thebase-view video stream and an elementary stream which, among theelementary streams obtained by the encoding, belongs to same reel set asthe base-view video stream.

In step S105, one sub-TS is obtained by multiplexing thereinto thedependent-view video stream and an elementary stream which, among theelementary streams obtained by the encoding, belongs to the same reelset as the dependent-view video stream.

In step S106, the prototype of the clip information file is createdbased on the parameters having been set during the encoding andmultiplexing.

In step S107, the playlist information is defined by generating theplayitem information and the sub-playitem information based on theprototype of the playitem, and then generating the main path informationand the sub-path information by defining the playback order based on theplayitem information and the sub-playitem information.

In the generation of the playitem information, the stream selectiontable is generated in the playitem information so that, among theelementary streams multiplexed in the main TS, elementary streams thatare defined, in the basic structure of the playitem, to be played backin the monoscopic output mode are set to “playable”. Also, to define theplayback section in the base-view video stream, the In_TIme and Out_TImehaving been defined by the above-described editing are written in theplayitem information.

In the generation of the sub-playitem information, the extension streamselection table is generated in the extension data of the playlistinformation so that, among the elementary streams multiplexed in thesub-main TS, elementary streams that are defined, in the basic structureof the playitem, to be played back in the stereoscopic output mode areset to “playable”. The playitem information and the sub-playiteminformation are defined based on information in the clip informationfile, and thus are set based on the prototype of the prototype of theclip information file.

In step S108, the main TS, sub-TS, prototype of the clip informationfile, and prototype of the playlist information are converted into adirectory file group in a predetermined application format.

Through the above-described processes, the main TS, sub-TS, clipinformation, playitem information, and sub-playitem information aregenerated. Then the main TS and the sub-TS are converted into respectiveindependent stream files, the clip information is converted into theclip information file, and the playitem information and the sub-playiteminformation are converted into the playlist information file. In thisway, a set of files to be recorded onto the recording medium areobtained.

After this, when the video stream encoding step is executed, the planeoffset value and the offset direction information obtained theabove-described conversion are written into the metadata of each GOP. Inthis way, the offset sequence can be generated in the encoding process.

FIG. 66 is a flow chart showing the procedure for writing the AV file.The AV files are written according to this flow chart when the recordingmethod by the real-time recording or the recording method including themastering or replication is implemented.

In step S401, the recording device generates the file entry in thememory of the recording device by creating “xxxxx.ssif”. In step S402,it is judged whether the continuous free sector regions have beenensured. When the continuous free sector regions have been ensured, thecontrol proceeds to step S403 in which the recording device writes thesource packet sequence constituting the dependent-view data block intothe continuous free sector regions as much as EXT2[i]. After this, stepsS404 through S408 are executed. When it is judged in step S402 that thecontinuous free sector regions have not been ensured, the controlproceeds to step S409 in which the exceptional process is performed, andthen the process ends.

The steps S404 through S408 constitute a loop in which the process ofsteps S404-S406 and S408 is repeated until it is judged “NO” in stepS407.

In step S405, the recording device writes the source packet sequenceconstituting the base-view data block into the continuous free sectorregions as much as EXT1[i]. In step S406, it adds, into the file entry,the allocation identifier that indicates the start address of the sourcepacket sequence and continuation length, and registers it as an Extent.In connection with this, it writes, into the metadata in the clip baseinformation and the clip dependent information, the Extent start pointinformation that indicates the start source packet number thereof.

The step S407 defines the condition for ending the loop. In step S407,it is judged whether or not there is a non-written source packet in thebase-view and dependent-view data blocks. When it is judged that thereis a non-written source packet, the control proceeds to step S408 tocontinue the loop. When it is judged that there is no non-written sourcepacket, the control proceeds to step S410.

In step S408, it is judged whether or not there are continuous sectorregions. When it is judged that there are continuous sector regions, thecontrol proceeds to step S403. When it is judged that there are nocontinuous sector regions, the control returns to step S402.

In step S410, “xxxxx.ssif” is closed and the file entry is written ontothe recording medium. In step S411, “xxxxx.m2ts” is created and the fileentry of “xxxxx.m2ts” is generated in the memory. In step S412, theallocation descriptor that indicates the continuation length and thestart address of Extent of the base-view data block unique to the file2D is added into the file entry of “xxxxx.m2ts”. In step S413,“xxxxx.m2ts” is closed and the file entry is written.

In step S404, it is judged whether or not there is a long jumpoccurrence point in the range of “EXTss+EXT2D”. In the present example,it is presumed that the long jump occurrence point is a boundary betweenlayers. When it is judged that there is a long jump occurrence point inthe range of “EXTss+EXT2D”, the control proceeds to step S420 in which acopy of the base-view data block is created, and base-view data blocksB[i]ss and B[i]2D are written into the region immediately before thelong jump occurrence point, and then the control proceeds to step S406.These become Extents of the file 2D and Extents of the file base.

The following explains specific values of EXT2D, EXT1[n], EXT2[n], andEXTss[n].

The lowermost value of EXT2D is determined so that, when a playback inthe 2D output mode is performed, a buffer under flow does not occur inthe read buffer of the playback device during a jump period from eachbase-view data block to the next base-view data block.

The lowermost value of EXT2D is represented by the following expressionfor Condition 1, when it takes Tjump2D(n) of time when a jump from then^(th) base-view data block to the (n+1)^(th) base-view data block ismade, each base-view data block is read into the read buffer at a speedof Rud2D, and the base-view data block is transferred from the readbuffer to the video decoder at an average speed of Rbext2D.[Lowermost value ofEXT2D]≧(Rud2D+Rbext2D)/(Rud2D−Rbext2D)×Tjump2D(n)  <Condition 1>

It is presumed here that an Extent corresponding to a base-view datablock B[n]ss is represented as EXT1[n]. In this case, the lowermostvalue of EXT1[n] is determined so that, when a playback in the B-Dpresentation mode is performed, a buffer under flow does not occur inthe double buffer during a jump period from each base-view data block tothe next dependent-view data block, and during a jump period from thedependent-view data block to the next base-view data block.

In the present example, the double buffer is composed of a read buffer 1and a read buffer 2. The read buffer 1 is the same as the read bufferprovided in the 2D playback device.

It is presumed here that, when a playback in the B-D presentation modeis performed, it takes Tfjump3D(n) of time when a jump from the n^(th)base-view data block to the p^(th) dependent-view data block is made,and it takes TBjump3D(n) of time when a jump from the p^(th)dependent-view data block to the (n+1)^(th) base-view data block ismade.

It is further presumed that, each base-view data block is read into theread buffer 1 at a speed of Rud3D, each dependent-view data block isread into the read buffer 2 at the speed of Rud3D, and the base-viewdata block is transferred from the read buffer 1 to the video decoder atan average speed of Rbext3D. Then the lowermost value of EXT1[n] isrepresented by the following expression for Condition 2. Thecontinuation length of the big Extents is set to a value that is equalto or higher than the lowermost value.[Lowermost value ofEXT1[n]]≧(Rud3D×Rbext3D)/(Rud3D−Rbext3D)×(TFjump3D(n)+EXT2[n]/(Rud3D+TBjump3D(n)))  <Condition2>

The lowermost value of EXT2 is determined so that, when a playback inthe B-D presentation mode is performed, a buffer under flow does notoccur in the double buffer of the playback device during a jump periodfrom each dependent-view Extent to the next base-view data Extent, andduring a jump period from the base-view Extent to the nextdependent-view Extent.

The lowermost value of EXT2[n] is represented by the followingexpression for Condition 3, when it takes Tfjump3D(n+1) of time when ajump from the (n+1)^(th) base-view data block to the (p+1)^(th)dependent-view data block is made, and the dependent-view data block istransferred from the read buffer 2 to the decoder at an average speed ofRdext3D.[Lowermost value ofEXT2[n]]≧(Rud3D+Rbext3D)/(Rud3D−Rdext3D)×(TBjump3D(n)+EXT2[n+1]/(Rud3D+TFjump3D(n+1)))  <Condition3>

<Specific Values of EXTSS>

When a jump from a reading of an Extent to the next Extent is to bemade, the buffer should be occupied by a sufficient amount of dataimmediately before the jump. Accordingly, when a stereoscopicinterleaved stream file is to be read, the read buffer needs to storeone Extent, and occurrence of a buffer under flow should be avoided.

However, the “EXTSS” needs to be determined based not only on “Tjump”, atime period taken when a jump from an Extent to another Extent, but on“Tdiff”. It should be noted here that the “Tdiff” represents a delaytime that occurs in connection with a preloading of dependent-view datablocks in EXTss and a preloading of dependent-view data blocks inEXTssnext. The following further explains the meaning of Tdiff. When astereoscopic interleaved stream file is read while the startingdependent-view data block is being preloaded.

In EXTss, the playback is delayed as much as the time period requiredfor preloading the dependent-view data block. Here, the time periodrequired for preloading the starting dependent-view data block in EXTssis referred to as “delay period” because the playback is delayed as muchas the period.

On the other hand, in EXTssnext, immediately after a jump from EXTss toEXTssnext is made, the starting dependent-view data block is preloaded.Thus the playback by the video decoder is allowed to be delayed for theperiod of the preloading. Therefore the time period in which thestarting dependent-view data block is preloaded in the playback ofEXTssnext is referred to as “grace period” because the start of playbackby the video decoder is allowed to be delayed for the period.

In view of this, a value of Tdiff is obtained by subtracting the delayperiod from the grace period of the dependent-view data block. Morespecifically, the value Tdiff is calculated using the followingexpression.Tdiff=ceil[((S1stEXT1[i]EXTSSnext)−S1stEXT1[i]EXTSS)×1000×8]/Rud72]

In the above expression, Tdiff means a difference between the timeperiod for reading S1stEXT2[i]EXTss and the time period for readingS1stEXT2[i]EXTSSnext; S1stEXT2[i]EXTss represents the size of EXT2[i]which is located at the start of EXTss; S1stEXT2[i]EXTssnext representsthe size of EXT2[i] which is located at the start of EXTssnext.EXTssnext is an Extent in the stereoscopic interleaved stream file, islocated immediately after EXTss, and is played back seamlessly withEXTss.

With use of Tdiff and Tjump, which is a time period required for jump toEXTssnext, Sextss, which is the minimum Extent size based on the averagebit rate in each Extent, is calculated as a value satisfying thefollowing Condition 4.SextSS[Byte]≧ceil[(Tjump+Tdiff×Rud72)/(1000×8)]×(Rextss×192)/(Rud72×188−Rextss×192)]  <Condition4>

In the above Condition 4, Rud72 represents a data rate in transfer fromthe BD-ROM drive in the stereoscopic output mode.

Rextss represents an average bit rate in EXTss and is obtained using thefollowing expressions.Rextss=ceil[Nsp×188×8/(ATCDextss/27000000)]ATCDextss=ATCstart_(—) EXTssnext−ATCstart_(—) EXTssATCDextss=ATClast_(—) EXTss−ATCstart_(—)EXTss+ceil(27000000×188×8/min(Rts1,Rts2))

In the above expressions, ATCDextss represents the ATC period of EXTss.

ATCstart_EXTss represents the minimum ATC value specified by the ATCfield of the source packet sequence in EXTss.

ATCstart_EXTssnext represents the minimum ATC value specified by the ATCfield of the source packet sequence in EXTssnext.

ATClast_EXTss represents the maximum ATC value specified by the ATCfield of the source packet sequence in EXTss.

Nsp represents the number of source packets which are included in themain TS and sub-TS and have ATC values corresponding to ATCs in therange of ATCDexss.

Rts1 represents a value of the TS recording rate in the main TS, and itsmaximum value is 48 Mbps.

Rts2 represents a value of the TS recording rate in the sub-TS, and itsmaximum value is 48 Mbps.

When two playitems are to be played back continuously, EXTss includesthe first byte of data in the ATC sequence that is used by the previousplayitem (Playitem 1).

-   -   EXTss has a size equal to or more than the minimum Extent size        defined in Condition 4.    -   When EXTss is the first byte of data in the ATC sequence that is        used by the previous playitem, the connection condition        information of the previous playitem is not set to “5” or “6”.        In this case, it is not necessary to satisfy the size of EXTss.

EXTss includes byte of data in the ATC sequence that is used by thecurrent playitem (Playitem 2).

-   -   EXTss has a size equal to or more than the minimum Extent size        defined in Condition 4.    -   When EXTss is the last byte of data in the ATC sequence that is        used by the Playitem 2, the connection condition information of        Playitem 2 is not set to “5” or “6”. In this case, it is not        necessary to satisfy the size of EXTss.

<Detailed Recording of Base-view Data Blocks and Dependent-view DataBlocks>

When GOPs of the main TS and sub-TS are to be recorded onto a recordingmedium, entries of the extension entry map point to only dependent-viewpicture data pieces that correspond to base-view picture data piecespointed to by entries of the basic entry map as those that are to beplayed back at the same playback times as the dependent-view picturedata pieces.

To realize such pointing, the recording process is performed as follows.

In the recording process, an attempt is made so that a boundary betweena dependent-view data block and a base-view data block matches aboundary between a dependent-view GOP and a base-view GOP. Morespecifically, in this attempt, the access unit delimiter of the startingvideo access unit of GOP(i) in the sub-TS is divided as a boundarybetween dependent-view data blocks, and the access unit delimiter of thestarting video access unit of GOP(i) in the main TS is divided as aboundary between base-view data blocks. In this division, therestriction on the Extent length described earlier should be satisfied.

In this division, when either a base-view data block or a dependent-viewdata block does not satisfy the restriction that the Extent should havea length that does not cause an underflow in a double buffer in theplayback device, a padding packet is inserted either into immediatelybefore the access unit delimiter of the starting video access unit ofGOP(i) in the sub-TS, or into immediately before the access unitdelimiter of the starting video access unit of GOP(i) in the main TS,and then the above-described attempt is made again so that theboundaries match.

When the boundaries match successfully by the above-described method, anentry pointing to a source packet number of a source packet storing theaccess unit delimiter of the starting access unit of the dependent-viewGOP is added into the extension entry map. Also, an entry pointing to asource packet number of a source packet storing the access unitdelimiter of the starting access unit of the base-view GOP is added intothe base entry map, as well.

When the boundaries do not match even if the padding packet is inserted,and the source packet storing the access unit delimiter of the startingaccess unit of the dependent-view GOP is in the middle of thedependent-view data block, an entry pointing to the source packet is notadded into the extension entry map. Similarly, when the source packetstoring the access unit delimiter of the starting access unit of thebase-view GOP is in the middle of the base-view data block, an entrypointing to the source packet is not added into the extension entry map.

When such entries are excluded from the extension entry map in this way,it is ensured that pairs of a base view and a dependent view are pointedto by the entries of the basic entry map and the extension entry map.

The process of recording base-view data blocks and dependent-view datablocks and then generating the entry maps is realized by a process inwhich the starts of GOPs are detected from the recorded stereoscopicinterleaved stream file, and entries pointing to the detected starts ofGOPs are added into the entry maps. The following describes theprocedure for generating the basic and extension entry maps by detectingthe starts of GOPs and adding the entries, with reference to FIG. 67.

FIG. 67 is a flow chart showing the procedure for generating the basicentry map and the extension entry map.

In step S601, forms of the basic entry map and the extension entry mapare generated in the memory, and the control proceeds to a loop composedof steps S602 through S610. In this loop, the variable x identifies aGOP. The loop is executed as follows. The variable x is initialized to 1(step S602). The start of GOP(x) is identified (step S603). An SPN(x)corresponding to the starting PTS(x) of the GOP is identified (stepS604). After this, judgments are performed in steps S605 and S607. Instep S605, it is judged whether or not SPN(x) is the start of EXT1[i].When it is judged that SPN(x) is not the start of EXT1[i], stepsS606-609 are skipped. When it is judged that SPN(x) is the start ofEXT1[i], the control proceeds to step S606 in which EXT2[j], whose startSPN(y) corresponds to PTS(x), is identified.

In step S607, it is judged whether or not variable “i” that identifiesEXT1[i] matches variable “j” that identifies EXT2[j]. When it is judgedthat variable “i” does not match variable “j”, the steps after this areskipped. When it is judged that variable “i” matches variable “j”,EP_entry(x) pointing to a pair of PTS(x) and SPN(x) is added into thebasic entry map (step S608), and EP_entry(x) pointing to a pair ofPTS(x) and SPN(y) is added into the extension entry map (step S609).

In step S610, it is judged whether or not variable x specifies the lastGOP. When it is judged that variable x does not specify the last GOP,variable x is incremented, and the control moves to step S603.

<Creation of Index Table>

The index table described in Embodiment 3 can be created in thefollowing manner. When the base-view video stream, dependent-view videostream, clip information file, and playlist information file aregenerated in accordance with the flow chart shown in FIG. 59, thedisplay frequencies of playlists to be recorded on the recording mediumare identified. Of these display frequencies, the resolution/displayfrequency of the playlist to be used in the first play title, or theresolution/display frequency of the playlist of the title specified bythe title number in the range from 0 to 999 is set in the video formatinformation and the frame rate information in the BDMV applicationinformation in the index table. With this structure, theresolution/display frequency to be applied to the display of theplaylist is set in the index table.

FIG. 68 is a flow chart showing the procedure for generating the BD-Japplication, BD-J object, movie object, and index table. In step S701, asource program, which instructs the playback device to generate a playerinstance for a playlist, is generated by the object-orientedprogramming. In step S702, a BD-J application is generated by compilingand archiving the generated source program.

In step S703, a BD-J object is generated. In step S704, a movie objectis described with use of a command that instructs playback of aplaylist. In step S705, an index table is generated by describingcorrespondence between title numbers and BD-J object or movie object. Instep S706, a playlist to be the first play title is selected. In stepS707, BDMV application information, which indicates the video format andvideo rate of the playlist in the first play title, is generated. Instep S708, an index table that includes the title index and the BDMVapplication information is generated. In step S709, BD-J object, theBD-J application, movie object, and index table are written onto therecording medium.

The following explains the recording medium that is generated by theabove-described recording.

FIG. 69 shows an internal structure of a multi-layered optical disc.

The first row of FIG. 69 shows one example of a multi-layered opticaldisc. The second row shows tracks in the horizontally extended formatthough they are in reality formed spirally in the recording layers.These spiral tracks in the recording layers are treated as onecontinuous volume region. The volume region is composed of a lead-inregion, recording layers of recording layers 1 through 3, and a lead-outregion, where the lead-in region is located at the inner circumference,the lead-out region is located at the outer circumference, and therecording layers of recording layers 1 through 3 are located between thelead-in region and the lead-out region. The recording layers ofrecording layers 1 through 3 constitute one consecutive logical addressspace.

The volume region is sectioned into units in which the optical disc canbe accessed, and serial numbers are assigned to the access units. Theserial numbers are called logical addresses. Data is read from theoptical disc by specifying a logical address. Here, in the case of aread-only disc such as the BD-ROM, basically, sectors with consecutivelogical addresses are also consecutive in the physical disposition onthe optical disc. That is to say, data stored in the sectors withconsecutive logical addresses can be read without performing a seekoperation. However, at the boundaries between recording layers,consecutive data reading is not possible even if the logical addressesare consecutive. It is thus presumed that the logical addresses of theboundaries between recording layers are registered in the recordingdevice in advance.

In the volume region, file system management information is recordedimmediately after the lead-in region. Following this, a partition regionmanaged by the file system management information exists. The filesystem is a system that expresses data on the disc in units calleddirectories or files. In the case of the BD-ROM, the file system is aUDF (Universal Disc Format). Even in the case of an everyday PC(personal computer), when data is recorded with a file system called FATor NTFS, the data recorded on the hard disk under directories and filescan be used on the computer, thus improving usability. The file systemmakes it possible to read logical data in the same manner as in anordinary PC, using a directory and file structure.

The fourth row shows how the regions in the file system region managedby the file system are assigned. As shown in the fourth row, a non-AVdata recording region exists on the innermost circumference side in thefile system region; and an AV data recording region exists immediatelyfollowing the non-AV data recording region. The fifth row shows thecontents recorded in the non-AV data recording region and the AV datarecording region. As shown in the fifth row, Extents constituting the AVfiles are recorded in the AV data recording region; and Extentsconstituting non-AV files, which are files other than the AV files, arerecorded in the non-AV data recording region.

FIG. 70 shows the application format of the optical disc based on thefile system.

The BDMV directory is a directory in which data such as AV content andmanagement information used in the BD-ROM are recorded. Fivesub-directories called “PLAYLIST directory,” “CLIPINF directory”,“STREAM directory”, “BDJO directory”, “JAR directory”, and “METAdirectory” exist below the BDMV directory. Also, two types of files(i.e. index.bdmv and MovieObject.bdmv) are arranged under the BDMVdirectory.

A file “index.bdmv” (the file name “index.bdmv” is fixed) stores anindex table.

A file “MovieObject.bdmv” (the file name “MovieObject. bdmv” is fixed)stores one or more movie objects. The movie object is a program filethat defines a control procedure to be performed by the playback devicein the operation mode (HDMV mode) in which the control subject is acommand interpreter. The movie object includes one or more commands anda mask flag, where the mask flag defines whether or not to mask a menucall or a title call when the call is performed by the user onto theGUI.

A program file (XXXXX.bdjo---“XXXXX” is variable, and the extension“bdjo” is fixed) to which an extension “bdjo” is given exists in theBDJO directory. The program file stores a BD-J object that defines acontrol procedure to be performed by the playback device in the BD-Jmode.

A substance of such a Java™ application is a Java™ archive file(YYYYY.jar) stored in the JAR directory under the BDMV directory.

An application may be, for example, a Java™ application that is composedof one or more xlet programs having been loaded into a heap memory (alsocalled work memory) of a virtual machine. The application is constitutedfrom the xlet programs having been loaded into the work memory, anddata.

In the “PLAYLIST directory”, a playlist information file(“xxxxx.mpls”---“XXXXX” is variable, and the extension “mpls” is fixed)to which an extension “mpls” is given exists.

In the “CLIPINF directory”, a clip information file(“xxxxx.clpi”---“XXXXX” is variable, and the extension “clpi” is fixed)to which an extension “clpi” is given exists.

The Extents constituting the files existing in the directories explainedup to now are recorded in the non-AV data region.

The “STREAM directory” is a directory storing a transport stream file.In the “STREAM directory”, a transport stream file(“xxxxx.m2ts”---“XXXXX” is variable, and the extension “m2ts” is fixed)to which an extension “m2ts” is given exists.

The above-described files are formed on a plurality of sectors that arephysically continuous in the partition region. The partition region is aregion accessed by the file system and includes an “region in which fileset descriptor is recorded”, “region in which end descriptor isrecorded”, “ROOT directory region”, “BDMV directory region”, “JARdirectory region”, “BDJO directory region”, “PLAYLIST directory region”,“CLIPINF directory region”, and “STREAM directory region”. The followingexplains these regions.

The “file set descriptor” includes a logical block number (LBN) thatindicates a sector in which the file entry of the ROOT directory isrecorded, among directory regions. The “end descriptor” indicates an endof the file set descriptor.

Next is a detailed description of the directory regions. Theabove-described directory regions have an internal structure in common.That is to say, each of the “directory regions” is composed of a “fileentry”, “directory file”, and “file recording region of lower file”.

The “file entry” includes a “descriptor tag”, an “ICB tag”, and an“allocation descriptor”.

The “descriptor tag” is a tag identifying, as a “file entry”, the fileentry which includes the descriptor tag itself.

The “ICB tag” indicates attribute information concerning the file entryitself.

The “allocation descriptor” includes a logical block number (LBN) thatindicates a recording position of the directory file. Up to now, thefile entry has been described. Next is a detailed description of thedirectory file.

The “directory file” includes a “file identification descriptor of lowerdirectory” and “file identification descriptor of lower file”.

The “file identification descriptor of lower directory” is informationthat is referenced to access a lower directory that belongs to thedirectory file itself, and is composed of identification information ofthe lower directory, the length of the directory name of the lowerdirectory, a file entry address that indicates the logical block numberof the block in which the file entry of the lower directory is recorded,and the directory name of the lower directory.

The “file identification descriptor of lower file” is information thatis referenced to access a file that belongs to the directory fileitself, and is composed of identification information of the lower file,the length of the lower file name, a file entry address that indicatesthe logical block number of the block in which the file entry of thelower file is recorded, and the file name of the lower file.

The file identification descriptors of the directory files of thedirectories indicate the logical blocks in which the file entries of thelower directory and the lower file are recorded. By tracing the fileidentification descriptors, it is therefore possible to reach from thefile entry of the ROOT directory to the file entry of the BDMVdirectory, and reach from the file entry of the BDMV directory to thefile entry of the PLAYLIST directory. Similarly, it is possible to reachthe file entries of the JAR directory, BDJO directory, CLIPINFdirectory, and STREAM directory.

The “file recording region of lower file” is a region in which thesubstance of the lower file that belongs to a directory. A “file entry”of the lower entry and one or more “Extents” are recorded in the “filerecording region of lower file”.

The stream file that constitutes the main feature of the presentapplication is a file recording region that exists in the directoryregion of the directory to which the file belongs. It is possible toaccess the transport stream file by tracing the file identificationdescriptors of the directory files, and the allocation descriptors ofthe file entries.

Embodiment 7

The present embodiment describes the internal structure of a 2D/3Dplayback device that has integrated functions of the playback deviceshaving been described in the embodiments so far.

FIG. 71 shows the structure of a 2D/3D playback device. The 2D/3Dplayback device includes a BD-ROM drive 1, a read buffer 2 a, a readbuffer 2 b, a switch 3, a system target decoder 4, a plane memory set 5a, a plane overlay unit 5 b, an HDMI transmission/reception unit 6, aplayback control unit 7, a memory, a register set 203, a programexecuting unit 11, a program memory 12, an HDMV module 13, a BD-Jplatform 14, a middleware 15, a mode management module 16, a user eventprocessing unit 17, a local storage 18, and a nonvolatile memory 19.

The BD-ROM drive 1, like a 2D playback device, reads out data from aBD-ROM disc based on a request from the playback control unit 7. AVclips read from the BD-ROM disc are transferred to the read buffer 2 aor 2 b.

When a 3D image is to be played back, the playback control unit 7 issuesa read request that instructs to read the base-view data block and thedependent-view data block alternately in units of Extents. The BD-ROMdrive 1 reads out Extents constituting the base-view data block into theread buffer 2 a, and reads out Extents constituting the dependent-viewdata block into the read buffer 2 b. When a 3D image is to be playedback, the BD-ROM drive 1 should have a higher reading speed than theBD-ROM drive for a 2D playback device, since it is necessary to readboth the base-view data block and the dependent-view data blocksimultaneously.

The read buffer 2 a is a buffer that may be realized by, for example, adual-port memory, and stores the data of the base-view data blocks readby the BD-ROM drive 1.

The read buffer 2 b is a buffer that may be realized by, for example, adual-port memory, and stores the data of the dependent-view data blocksread by the BD-ROM drive 1.

The switch 3 is used to switch the source of data to be input into theread buffers, between the BD-ROM drive 1 and the local storage 18.

The system target decoder 4 decodes the streams by performing thedemultiplexing process onto the source packets read into the read buffer2 a and the read buffer 2 b.

The plane memory set 5 a is composed of a plurality of plane memories.The plane memories include those for storing a left-view video plane, aright-view video plane, a secondary video plane, an interactive graphicsplane (IG plane), and a presentation graphics plane (PG plane).

The plane overlay unit 5 b performs the plane overlaying explained theembodiments so far. When the image is to be output to the television orthe like, the output is conformed to the 3D system. When it is necessaryto play back the left-view image and the right-view image alternately byusing the shutter glasses, the image is output as it is. When the imageis to be output to, for example, the lenticular television, a temporarybuffer is prepared, the left-view image is first transferred into thetemporary buffer, and the left-view image and the right-view image areoutput simultaneously after the right-view image is transferred.

The HDMI transmission/reception unit 6 executes the negotiation phasedescribed in Embodiment 1 in conformance with, for example, the HDMIstandard, where HDMI stands for High Definition Multimedia Interface. Inthe negotiation phase, the HDMI transmission/reception unit 6 canreceive, from the television, (i) information indicating whether or notit supports a stereoscopic display, (ii) information regardingresolution for a monoscopic display, and (iii) information regardingresolution for a stereoscopic display.

The playback control unit 7 includes a playback engine 7 a and aplayback control engine 7 b. When it is instructed from the programexecuting unit 11 or the like to play back a 3D playlist, the playbackcontrol unit 7 identifies a base-view data block of a playitem that isthe playback target among the 3D playlist, and identifies adependent-view data block of a sub-playitem in the 3D sub-path thatshould be played back in synchronization with the playitem. After this,the playback control unit 7 interprets the entry map of thecorresponding clip information file, and requests the BD-ROM drive 1 toalternately read the Extent of the base-view data block and the Extentof the dependent-view data block, starting with the playback startpoint, based on the Extent start type that indicates which of an Extentconstituting the base-view video stream and an Extent constituting thedependent-view video stream is disposed first. When the playback isstarted, the first Extent is read into the read buffer 2 a or the readbuffer 2 b completely, and then the transfer from the read buffer 2 aand the read buffer 2 b to the system target decoder 4 is started.

The playback engine 7 a executes AV playback functions. The AV playbackfunctions in the playback device are a group of traditional functionssucceeded from CD and DVD players. The AV playback functions include:Play, Stop, Pause On, Pause Off, Still Off, Forward Play (withspecification of the playback speed by an immediate value), BackwardPlay (with specification of the playback speed by an immediate value),Audio Change, Picture Data Change for Secondary Video, and Angle Change.

The playback control engine 7 b performs playlist playback functions inresponse to function calls from the command interpreter which is themain operating body in the HDMV mode, and from the Java platform whichis the main operating body in the BD-J mode. The playlist playbackfunctions mean that, among the above-described AV playback functions,the Play and Stop functions are performed in accordance with the currentplaylist information and the current clip information, where the currentplaylist information constitutes the current playlist.

The memory is a memory for storing the current playlist information andthe current clip information. The current playlist information is apiece of playlist information that is currently a target of processing,among a plurality of pieces of playlist information that can be accessedfrom the BD-ROM, built-in medium drive, or removable medium drive. Thecurrent clip information is a piece of clip information that iscurrently a target of processing, among a plurality of pieces of clipinformation that can be accessed from the BD-ROM, built-in medium drive,or removable medium drive.

The register set 10 is a player status/setting register set that is aset of registers including a general-purpose register for storingarbitrary information that is to be used by contents, as well as theplayback status register and the playback setting register having beendescribed in the embodiments so far.

The program executing unit 11 is a processor for executing a programstored in a BD program file. Operating according to the stored program,the program executing unit 11 performs the following controls: (1)instructing the playback control unit 7 to play back a playlist; and (2)transferring, to the system target decoder, PNG/JPEG that represents amenu or graphics for a game so that it is displayed on the screen. Thesecontrols can be performed freely in accordance with construction of theprogram, and how the controls are performed is determined by the processof programming the BD-J application in the authoring process.

The program memory 12 stores a current dynamic scenario which isprovided to the command interpreter that is an operator in the HDMVmode, and to the Java™ platform that is an operator in the BD-J mode.The current dynamic scenario is a current execution target that is oneof Index.bdmv, BD-J object, and movie object recorded in the BD-ROM. Theprogram memory 12 includes a heap memory.

The heap memory is a stack region for storing byte codes of the systemapplication, byte codes of the BD-J application, system parameters usedby the system application, and application parameters used by the BD-Japplication.

The HDMV module 13 is provided with a command interpreter, and controlsthe HDMV mode by decoding and executing the navigation command whichconstitutes the movie object.

The BD-J platform 14 is a Java™ platform that is an operator in the BD-Jmode, and is fully implemented with Java™ 2 Micro_Edition (J2ME)Personal Basis Profile (PBP 1.0), and Globally Executable MHPspecification (GEM1.0.2) for package media targets. The BD-J platform 14is composed of a class loader, a byte code interpreter, and anapplication manager.

The class loader is one of system applications, and loads a BD-Japplication by reading byte codes from the class file existing in theJAR archive file, and storing the byte codes into the heap memory.

The byte code interpreter is what is called a Java™ virtual machine. Thebyte code interpreter converts (i) the byte codes constituting the BD-Japplication stored in the heap memory and (ii) the byte codesconstituting the system application, into native codes, and causes theMPU to execute the native codes.

The application manager is one of system applications, and performsapplication signaling for the BD-J application based on the applicationmanagement table in the BD-J object, such as starting or ending a BD-Japplication. This completes the internal structure of the BD-J platform.

The middleware 15 is an operating system for the embedded software, andis composed of a kernel and a device driver. The kernel provides theBD-J application with a function unique to the playback device, inresponse to a call for the Application Programming Interface (API) fromthe BD-J application. The middleware 15 also realizes controlling thehardware, such as starting the interruption handler by sending aninterruption signal.

The mode management module 16 holds Index.bdmv that was read from theBD-ROM, built-in medium drive, or removable medium drive, and performs amode management and a branch control. The management by the modemanagement is a module assignment to cause either the BD-J platform orthe HDMV module to execute the dynamic scenario.

The user event processing unit 17 receives a user operation via a remotecontrol, and causes the program executing unit 11 or the playbackcontrol unit 7 to perform a process as instructed by the received useroperation. For example, when the user presses a button on the remotecontrol, the user event processing unit 17 instructs the programexecuting unit 11 to execute a command included in the button. Forexample, when the user presses a fast forward/rewind button on theremote control, the user event processing unit 17 instructs the playbackcontrol unit 7 to execute the fast forward/rewind process onto the AVclip of the currently played-back playlist.

The local storage 18 includes the built-in medium drive for accessing ahard disc, and the removable medium drive for accessing a semiconductormemory card, and stores downloaded additional contents, data to be usedby applications, and other data. A region for storing the additionalcontents is divided into as many small regions as BD-ROMs. Also, aregion for storing data used by applications is divided into as manysmall regions as the applications.

The nonvolatile memory 19 is a recording medium that is, for example, areadable/writable memory, and is a medium such as a flash memory orFeRAM that can preserve the recorded data even if a power is notsupplied thereto. The nonvolatile memory 19 is used to store a backup ofthe register set 203.

Embodiment 8

The present embodiment is an embodiment for implementing an inventionthat is the same as the invention (hereinafter referred to as “presentinvention”) recited in the description and the drawings attached to arequest for a patent application which is a basis of the prioritydeclaration of the present application.

Firstly, of the implementation acts of the recording medium of thepresent invention, an embodiment of a usage act is described. FIG. 72Ashows the embodiment of a usage act of a recording medium relating tothe present invention. A BD-ROM 101 in FIG. 72A is a recording mediumpertaining to the present invention. The BD-ROM 101 is used to supplymovies to a home theater system composed of a playback device 102, atelevision 103, and a remote control 104.

This completes the description of the usage act of the recording mediumrelating to the present invention.

The following describes the data structure of a BD-ROM (i.e., arecording medium of the present invention) for recording 2D images.

FIG. 72B shows the structure of the BD-ROM.

The fourth row in FIG. 72B shows the BD-ROM 101, and the third row showsa track on the BD-ROM. Although the track is usually formed to extendspirally from an inner circumference to an outer circumference, thetrack is drawn in a laterally expanded manner in the present figure. Aswith other optical discs such as DVDs and CDs, the BD-ROM 101 has arecording region that spirals from the inner circumference to the outercircumference of the BD-ROM 101. The BD-ROM 101 also has a volume regionin which logical data can be recorded, between the lead-in on the innercircumference side and the lead-out on the outer circumference side. Thevolume region is sectioned into units in which the optical disc can beaccessed, and serial numbers are assigned to the access units. Theserial numbers are called logical addresses. Data is read out from theoptical disc by specifying logical addresses. It is defined here thatthe logical addresses also indicate physically consecutive regions onthe optical disc. That is to say, data with consecutive logicaladdresses can be read without a seek operation. There is a special areacalled BCA (Burst Cutting Area) provided at a place more inner than thelead-in. Since it can be read only by a drive, not by an application,the BCA is often used by the copyright protection technology.

At the head of the volume region, volume information of a file system isrecorded, followed by application data such as video data. The filesystem is a system that expresses data on the disc in units ofdirectories and files. In the BD-ROM 101, the file system is recorded ina format called UDF (Universal Disc Format). Even in the case of aneveryday PC (Personal Computer), when data is recorded with a filesystem called FAT or NTFS, the data recorded on the hard disk underdirectories and files can be used on the computer, thus improvingusability. The file system makes it possible to read logical data in thesame manner as in an ordinary PC, using a directory and file structure.

The directory and file structure on the BD-ROM 101 is as follows. A BDMVdirectory is provided directly below a root directory (ROOT). Data suchas AV contents and management information on the BD-ROM 101 is recordedin the BDMV directory. Provided below the BDMV directory are an indexfile (index.bdmv) defining an index table constituting a title, aPLAYLIST directory, a CLIPINF directory, a STREAM directory, a BDJOdirectory, and a JAR directory. Provided below the STREAM directory,CLIPINF directory and PLAYLIST directory are: an AV clip (XXX.M2TS)storing AV contents such as video and audio that are multiplexedtogether; a clip information file (XXX.CLPI) storing AV clip managementinformation; a playlist file (YYY.MPLS) defining logical playback pathsof AV clips; and a BD program file (AAA.PROG) storing a program thatdefines a dynamic scenario.

The following describes the data structure of the files that are storedunder the BDMV directory.

The index file (Index.bdmv) is described first. The index file has theindex table shown in FIG. 72C. The index table is a table that isprovided in the highest layer and defines the title structure of the topmenu, FirstPlay, and all titles stored on the BD-ROM. The index tablespecifies program files to be executed first from each title, the topmenu, and the FirstPlay. Each time a title or a menu is called, a BD-ROMplayer refers to the index table, to execute a predetermined BD programfile. Here, FirstPlay is set by a content provider, and indicates a BDprogram file to be executed automatically when the disc is loaded into aBD-ROM player. The top menu specifies a movie object or a BD-J objectwhich is to be called when a command “Return to the menu” is executedaccording to a user operation via a remote controller.

The BD program file (AAA.PRG) stores a plurality of programs to bespecified and executed from each title. Different prefixes (e.g., AAA)are used to identify corresponding files. Although interpreter-approachprograms with unique specifications are used to generate programs forBlu-ray Disc, the programs to be used may be written in ageneral-purpose programming language such as Java™ or Java™ Script. Theprogramming language is not essential to the present invention. Theprograms specify playlists to be played back.

A description is now given on the AV clip (XXX.M2TS) and the clipinformation file (XXX.CLPI).

The AV clip is a digital stream having an MPEG-2 transport streamformat.

FIG. 73A shows the structure of an AV clip. As shown in FIG. 73A, an AVclip is obtained by multiplexing one or more of the video stream, audiostream, presentation graphics stream (PG), and interactive graphicsstream (IG). The video stream represents the primary and secondaryvideos of a movie. The audio stream represents the primary audio of themovie and the secondary audio to be mixed with the primary audio. Thepresentation graphics stream represents subtitles for the movie. Notethat the primary video is an ordinary video displayed on the screen, andthe secondary video is displayed in a small screen provided withindisplay of the primary video. The interactive graphics stream representsan interactive screen created by disposing GUI components on a screen.The video stream is encoded by an encoding method such as MPEG-2, MPEG-4AVC, or SMPTE VC-1 before it is recorded. The audio stream iscompress-encoded by a method such as Dolby AC-3, Dolby Digital Plus,MLP, DTS, DTS-HD, or linear PCM before it is recorded.

Described below is the structure of the video stream. When a videocompression/encoding technique such as MPEG-2, MPEG-4 AVC and SMPTE VC-1is used, data is compressed in size by taking advantage of spatial andtemporal redundancy of the video. One method that takes advantage oftemporal redundancy of the video is inter-picture predictive encoding.According to the inter-picture predictive encoding, when encoding acertain picture, another picture to be displayed before or after thecertain picture along the display time axis is designated as a referencepicture. After detecting a motion amount by which data of the certainpicture differs from data of the reference picture, the data of thecertain picture is compressed in size by removing the spatialredundancy, which is obtained by subtracting the certain picture (targetof encoding) from the motion-compensated reference picture.

An I-picture is a picture that is encoded by inter-picture predictiveencoding—i.e., by only using information present in itself withoutreferring to a reference picture. It should be noted that a “picture” isa unit of encoding and denotes both of a frame and a field. A P-pictureis a picture that is encoded by inter-picture predictive encoding—morespecifically, by referring to another picture that has already beenprocessed. A B-picture is a picture that is encoded by inter-picturepredictive encoding—more specifically, by simultaneously referring toother two pictures that have already been processed. A B-picture that isreferred to by another picture is called a “Br-picture”. A frame (in thecase of the frame structure) and a field (in the case of the fieldstructure) are called video access units.

Each stream in the AV clip is identified by a PID. For example, analignment 0x1011 is allocated to a video stream used as the video of themovie, alignments 0x1100 to 0x111F are allocated to the audio streams,alignments 0x1200 to 0x121F are allocated to the presentation graphics,alignments 0x1400 to 0x141F are allocated to the interactive graphicsstreams, alignments 0x1B00 to 0x1B1F are allocated to the video streamsused as secondary video of the movie, and alignments 0x1A00 to 0x1A1Fare allocated to the audio stream used as secondary audio mixed with theprimary audio.

FIG. 73B schematically shows how the AV clip is multiplexed. Firstly, avideo stream 501 composed of a plurality of video frames and an audiostream 504 composed of a plurality of audio frames are converted into aPES packet series 502 and a PES packet series 505, respectively. The PESpacket series 502 and 505 are converted into TS packets 503 and 506,respectively. Similarly, data pieces of a presentation graphics stream507 and interactive graphics 510 are converted into a PES packet series508 and a PES packet series 511, respectively, and the PES packet series508 and 511 are converted into TS packets 509 and 512, respectively. AnAV clip 513 is composed of the TS packets 503, 506, 509, and 512multiplexed on one stream.

FIG. 74A illustrates in more detail how the video stream is stored inthe PES packet series. The first row shows a video frame series of thevideo stream. The second row shows a PES packet series. As shown byarrows yy1, yy2, yy3 and yy4, the video stream is composed of aplurality of video presentation units (I-picture, B-picture, P-picture).The video stream is divided up into the individual pictures, and eachpicture is stored in the payload of a PES packet. Each PES packet has aPES header storing a PTS (Presentation Time-Stamp) that indicates adisplay time of the picture stored in the payload of the PES packet, anda DTS (Decoding Time-Stamp) that indicates a decoding time of thepicture stored in the payload of the PES packet

FIG. 74B shows the format of the TS packets ultimately written in the AVclip. Each TS packet is a fixed-length, 188-byte packet composed of a4-byte TS header carrying information such as a PID identifying thestream, and a 184-byte TS payload storing data. The PES packets arestored in the divided form in the TS payloads. In the case of BD-ROM,each TS packet is attached a 4-byte TP_Extra_Header, thus constituting a192-byte source packet. The source packets are written in the AV clip.The TP_Extra_Header stores information such as an ATS(Arrival_Time_Stamp). The ATS shows a transfer start time at which theTS packet is to be transferred to a PID filter of a system targetdecoder 1503, which will be described later. The source packets arearranged in the AV clip as shown on the lower row in FIG. 74B. Thenumbers incrementing from the head of the AV clip are called SPNs(Source Packet Numbers).

In addition to TS packets of audio, video, subtitles and the like, theAV clip also includes TS packets of a PAT (Program Association Table), aPMT (Program Map Table) and a PCR (Program Clock Reference). The PATshows a PID of a PMT used in the AV clip. The PID of the PAT itself isregistered as “0”. The PMT stores the PIDs in the streams of video,audio, subtitles and the like, and attribute information correspondingto the PIDs. The PMT also has various descriptors relating to the AVclip. The descriptors have information such as copy control informationshowing whether copying of the AV clip is permitted or not permitted.The PCR stores STC time information corresponding to an ATS showing whenthe PCR packet is transferred to a decoder, in order to achievesynchronization between an ATC (Arrival Time Clock) that is a time axisof ATSs, and an STC (System Time Clock) that is a time axis of PTSs andDTSs.

FIG. 75A explains the data structure of the PMT in detail. A PMT headeris disposed at the top of the PMT. Information written in the PMT headerincludes the length of data included in the PMT to which the PMT headeris attached. A plurality of descriptors relating to the AV clip isdisposed after the PMT header. Information such as the described copycontrol information is listed in the descriptors. After the descriptorsis a plurality of pieces of stream information relating to the streamsincluded in the AV clip. Each piece of stream information is composed ofstream descriptors, each listing information such as a stream type foridentifying the compression codec of the stream, a stream PID, or streamattribute information (such as frame rate or aspect ratio). The numberof stream descriptors is equal to that of streams in the AV clip.

As shown in FIG. 75B, each piece of clip information file is managementinformation for an AV clip. The clip information files are in one to onecorrespondence with the AV clips, and are each composed of clipinformation, stream attribute information, and entry map.

As shown in FIG. 75B, clip information is composed of a system rate, aplayback start time, and a playback end time. The system rate representsa maximum transfer rate at which the AV clip is transferred to the PIDfilter of the system target decoder, which will be described later. Theinterval between the ATSs in the AV clip is equal to or lower than thesystem rate. The playback start time is the PTS of the first video framein the AV clip. The playback end time is obtained by adding a per-frameplayback interval to the PTS of the last video frame in the AV clip.

As shown in FIG. 76A, a piece of attribute information is registered foreach PID of each stream in the AV clip. Each piece of attributeinformation has different information depending on whether thecorresponding stream is a video stream, an audio stream, a presentationgraphics stream, or an interactive graphics stream. Each piece of videostream attribute information carries information including what kind ofcompression codec the video stream was compressed with, and theresolution, aspect ratio and frame rate of the pieces of picture datathat compose the video stream. Each piece of audio stream attributeinformation carries information including what kind of compression codecthe audio stream was compressed with, how many channels are included inthe audio stream, how many languages the audio stream supports, and thesampling frequency. The information in the video stream attributeinformation and the audio stream attribute information is used forpurposes such as initialization of a decoder before the player performsplayback.

As shown in FIG. 76B, the entry map is table information that showsentry map header information 1101, PTSs, and SPNs. Each PTS shows adisplay time of each I-picture in the video stream in the AV clip. EachSPN is the SPN of the AV clip that is started with an I-picture. Here, apair of a PTS and an SPN shown in a same row in the table is called an“entry point”. Each entry point has an entry point ID (hereinafter alsoreferred to as an “EP_ID”). Starting with the top entry point, which hasan entry point ID 0, the entry points have successively incrementedentry point IDs. Using the entry map, the player can specify thelocation of a file of an AV clip corresponding to an arbitrary point onthe playback axis of the video stream. For instance, when performingspecial playback such as fast forward or rewind, the player can performprocessing efficiently without analyzing the AV clip, by specifying,selecting and playing back an I-picture registered in the entry map. Anentry map is created for each video stream multiplexed in the AV clip.The entry maps are managed according to PIDs. The entry map headerinformation 1101 is stored at the head of each entry map. The entry mapheader information 1101 carries information such as the PID of thecorresponding video stream and the number of entry points.

A description is now given of the playlist file (YYY.MPLS).

A playlist indicates the playback path of an AV clip. As shown in FIG.77A, a playlist is composed of one or more playitems 1201. Each playitemshows a playback segment with respect to an AV clip. The playitems 1201are each identified by a respective playitem ID, and are written in theorder in which they are to be played in the playlist. Furthermore, theplaylist includes an entry mark 1202 showing a playback start point. Theentry mark 1202 can be assigned in the playback segments defined in theplayitem. As shown in FIG. 77A, entry marks 1202 are assigned topositions that are potential playback start positions in playitems, andused for cued playback. In the case of a Movie title, for instance, theentry marks 1202 may be assigned to the head of each chapter, thusmaking chapter playback possible. It should be noted that the playbackpath of a series of playitems is defined as a main path 1205 in thepresent example.

The content of the playitems is now described with reference to FIG.77B. A playitem includes clip information 1301 of the clip to be playedback, a playback start time 1302, a playback end time 1303, a connectioncondition 1310, and a stream selection table 1305. Since the playbackstart time and the playback end time are time information, the playerrefers to the entry map of the clip information file, acquires an SPNcorresponding to the designated playback start time and playback endtime, and designates a read start position, to perform playbackprocessing.

The connection condition 1310 shows a previous playitem and a connectiontype. When the connection condition 1310 of a playitem is “1”, it is notguaranteed that the AV clip indicated by this playitem is seamlesslyconnected with another AV clip indicated by a previous playitem thatprecedes this playitem. When the connection condition 1310 of a playitemis “5” or “6”, it is guaranteed that the AV clip indicated by thisplayitem is seamlessly connected with another AV clip indicated by aprevious playitem that precedes this playitem. When the connectioncondition 1310 is “5”, an STC of one playitem and an STC of anotherplayitem does not need to be continuous with each other. That is to say,the video display start time of a start of an AV clip indicated by apost-connection playitem may not be continuous from the video displaystart time of an end of an AV clip indicated by a pre-connectionplayitem. However, in the case where the AV clip indicated by thepre-connection playitem and the AV clip indicated by the post-connectionplayitem are input to the PID filter of the system target decoder 1503and sequentially played back, these AV clips should not crash thedecoding ability of the system target decoder 1503. Also, there areseveral conditions that must be met. For example, the last frame of theaudio in the AV clip indicated by the pre-connection playitem mustoverlap the first frame of the audio in the AV clip indicated by thepost-connection playitem on the playback time axis. Also, in the casewhere the connection condition 1310 is “6”, when the AV clips indicatedby the pre-connection and post-connection playitems are combinedtogether, they must be playable as a single AV clip. In other words, anSTC and ATC of the AV clip indicated by the pre-connection playitem arecontinuous, and an STC and ATC of the AV clip indicated by thepost-connection playitem are continuous.

The stream selection table 1305 is composed of a plurality of streamentries 1309. Each stream entry 1309 is composed of a stream selectionnumber 1306, stream path information 1307 and stream identificationinformation 1308. The stream selection numbers 1306 are numbers thatincrement in order from the first stream entry 1309 included in thestream selection table. The stream selection numbers 1306 are used forstream identification in the player. The stream path information 1307 isinformation showing which AV clip the stream shown by the streamidentification information 1308 is multiplexed on. For example, if thestream path information 1307 shows “main path”, this indicates the AVstream of the playitem. If the stream path information 1307 shows“sub-path ID=1”, this indicates an AV clip of a sub-playitemcorresponding to a playback segment of the playitem. Specifics of thesub-path will be described in the next section. The streamidentification information 1308 is information such as PIDs, and showsstreams multiplexed on the AV clip being referred to. Furthermore,stream attribute information is also recorded in the stream entries1309. Each stream attribute information is a piece of informationshowing a property of a stream, and for instance includes a languageattribute in the case of audio, presentation graphics, or interactivegraphics.

As shown in FIG. 77C, a playlist may have one or more sub-paths. Thesub-paths are assigned IDs in the order they are registered in theplaylist. These IDs are used as sub-path IDs for identifying thesub-paths. Sub-paths are a series of playback paths played back insynchronization with a main path. As with a playitem, a sub-playitem hasthe clip information 1301 of the clip to be played back, the playbackstart time 1302, and the playback end time 1303. The playback start time1302 and the playback end time 1303 of the sub-playitem are expressedusing the same time axis as the main path. For example, if a certainstream entry 1309 registered in the stream selection table 1305 of theplayitem #2 shows sub-path ID=0 and presentation graphics 1, thepresentation graphics 1 multiplexed on the AV clip of the sub-playitem#2 played back in synchronization with the playback segment of theplayitem #2, among the sub-paths of sub-path ID=0, will be played backin the playitem #2 playback segment. Furthermore, a sub-playitemincludes a field called an SP connection condition, which has the samemeaning as a connection condition of a playitem. An AV clip on a borderbetween sub-playitems whose SP connection conditions are “5” or “6”needs to meet the conditions that the stated playitems whose connectionconditions are “5” or “6” need to meet.

This concludes the description of the data structure of the BD-ROM(i.e., a recording medium relating to the present invention) forrecording thereon 2D images.

A description is now given of a playback device (2D playback device)relating to the present invention, the playback device playing back aBD-ROM having 2D images recorded thereon.

FIG. 78A shows the structure of a 2D playback device 1500. The 2Dplayback device 1500 is composed of a BD-ROM drive 1501, a read buffer1502, a system target decoder 1503, a program memory 1504, a managementinformation memory 1505, a program execution unit 1506, a playbackcontrol unit 1507, a player variable 1508, a user event processing unit1509, and a plane adder 1510.

The BD-ROM drive 1501 reads data from a BD-ROM disc based on a requestfrom the playback control unit 1507. An AV clip read from the BD-ROMdisc is transferred to the read buffer 1502. An index file, a playlistfile, and a clip information file read from the BD-ROM disc aretransferred to the management information memory 1505. A movie objectfile read from the BD-ROM disc is transferred to the program memory1504.

The read buffer 1502 is a buffer constituted from a memory or the likethat stores data read using a BD-ROM drive. The management informationmemory 1505 is a buffer constituted from a memory or the like thatstores management information on the index file, playlist file and clipinformation file. The program memory 1504 is a buffer constituted from amemory or the like that stores the movie object file.

The system target decoder 1503 performs (i) demultiplexing processing onsource packets read into the read buffer 1502 and (ii) processing todecode streams. Information necessary to decode streams included in anAV clip, such as codec types and stream attributes, is transferred fromthe playback control unit 1507. The system target decoder 1503 writesthe decoded primary video stream, secondary video stream, interactivegraphics stream, and presentation graphics stream in their planememories, namely a primary video plane, a secondary video plane, aninteractive graphics plane (IG plane), and a presentation graphics plane(PG plane), respectively. The system target decoder 1503 also mixes thedecoded primary audio stream with the decoded secondary audio stream,and outputs the mixed streams to a speaker or the like. The systemtarget decoder 1503 also performs processing to decode graphics datasuch as JPEG and PNG (transferred from the program execution unit 1506)for display of a menu or the like, and to write the decoded graphicsdata to an image plane. Details of the system target decoder 1503 aregiven later.

The user event processing unit 1509 requests processing by the programexecution unit 1506 or the playback control unit 1507 in response to auser operation made through the remote control. For instance, when abutton on the remote control is pressed, the user event processing unit1509 makes a request to the program execution unit 1506 to execute acommand included in the button. As another example, when a fast forwardor rewind button in the remote control is pressed, the user eventprocessing unit 1509 instructs the playback control unit 1507 to executefast forward or rewind processing of the AV clip of the playlistcurrently being played back.

The playback control unit 1507 has the function of controlling playbackof the AV clip by controlling the BD-ROM drive 1501 and the systemtarget decoder 1503. The playback control unit 1507 also controlsplayback processing of an AV clip by interpreting playlist informationbased on a playback instruction from the program execution unit 1506 ornotification by the user event processing unit 1509. Furthermore, theplayback control unit 1507 also performs setting and referencing of theplayer variable 1508, and performs playback operations.

The player variable 1508 includes system parameters ( ) indicating thestatus of the player, and general parameters (GPRM) for general use.

FIG. 78B is a list of the system parameters (PSR).

PSR0: Language Code

PSR1: Primary audio stream number

PSR2: Subtitle stream number

PSR3: Angle number

PSR4: Title number

PSR5: Chapter number

PSR6: Program number

PSR7: Cell number

PSR8: Selected key information

PSR9: Navigation timer

PSR10: Playback time information

PSR11: Mixing mode for Karaoke

PSR12: Country information for parental management

PSR13: Parental level

PSR14: Player configuration value (video)

PSR15: Player configuration value (audio)

PSR16: Language code for audio stream

PSR17: Language code extension for audio stream

PSR18: Language code for subtitle stream

PSR19: Language code extension for subtitle stream

PSR20: Player region code

PSR21: User's preferential selection of 2D/3D output mode

PSR22: Current 2D/3D output mode

PSR23: 3D video output capability of display

PSR24: 3D image playback capability

PSR25: Reserved

PSR26: Reserved

PSR27: Reserved

PSR28: Reserved

PSR29: Reserved

PSR30: Reserved

PSR31: Reserved

The PSR10 is updated every time picture data belonging to an AV clip isdisplayed. In other words, if the playback device causes a new piece ofpicture data to be displayed, the PSR10 is updated to show the displaytime (PTS) of the new picture. The current playback point can be knownby referring to the PSR10.

The language code for the audio stream of the PSR16 and the languagecode for the subtitle stream of the PSR18 are items that can be set inthe OSD of the player or the like, and show default language codes ofthe player. For example, the BD program file may have the followingfunction. Namely, if the language code for audio stream PSR16 isEnglish, when a playlist is played back, a stream entry having the samelanguage code is searched for in the stream selection table of theplayitem, and the corresponding audio stream is selected and playedback.

Furthermore, the playback control unit 1507 checks the status of thesystem parameter while playback is performed. The PSR1, PSR2, PSR21 andPSR22 show the audio stream number, subtitle stream number, secondaryvideo stream number and secondary audio stream number, respectively.These values correspond to the stream selection number 606. As oneexample, the audio stream number PSR1 may be changed by the programexecution unit 1506. The playback control unit 1507 compares the streamsection number 606 from among the stream selection table 605 of theplayitem currently being played back, refers to the matching streamentry 609, and switches playback of the audio stream. In this way,switches can be made between which audio, subtitle or secondary videostream is played back or not.

The program execution unit 1506 is a processor for executing a programstored in the BD program file. The program execution unit 1506 performsoperations in accordance with the stored program, and performs controlas follows. (1) The program execution unit 1506 instructs the playbackcontrol unit 1507 to perform playlist playback. (2) The programexecution unit 1506 transfers PNG/JPEG for graphics for a menu or a gameto the system target decoder, for display on a screen. These operationscan be performed flexibly in accordance with the makeup of the programs.What kind of control is performed is determined according to programmingprocedure of the BD program file in the authoring procedure.

The plane adder instantaneously superimposes data pieces written in theprimary video plane, the secondary video plane, the interactive graphicsplane, the presentation graphics plane and the image plane, and displaysthe resultant superimposed data on the screen of a television or thelike.

A description of the system target decoder 1503 is now given withreference to FIG. 79.

The source depacketizer interprets a source packet transferred to thesystem target decoder 1503, extracts the TS packet, and sends the TSpacket to the PID filter. In sending the TS packet, the sourcedepacketizer adjusts the time of input into the decoder in accordancewith the ATS of the source packet. More specifically, in accordance withthe rate of storing an AV clip, the source depacketizer transfers the TSpacket to the PID filer at the instant that the value of the ATCgenerated by the ATC counter and the value of the ATS of the sourcepacket become identical.

The PID filters transfer TS packets output from the sourcedepacketizers. More specifically, the PID filters transfer TS packetshaving a PID that matches a PID required for playback to the primaryvideo decoder, the secondary video decoder, the IG decoder, the PGdecoder, the audio decoder or the secondary audio decoder, depending onthe PID of the TS packet. For instance, in the case of the BD-ROM, a TSpacket having a PID 0x1011 is transferred to the primary video decoder,TS packets having PIDs 0x1B00 to 0x1B1F are transferred to the secondaryvideo decoder, TS packets having PIDs 0x1100 to 0x111F are transferredto the primary audio decoder, TS packets having PIDs 0x1A00 to 0x1A1Fare transferred to the secondary audio decoder, TS packets having PIDs0x1200 to 0x121F are transferred to the PG decoder, and TS packetshaving PIDs 0x1400 to 0x141F are transferred to the IG decoder.

The primary video decoder is composed of a TB (Transport Stream Buffer)1701, an MB (Multiplexing Buffer) 1702, an EB (Elementary Stream Buffer)1703, a compressed video decoder 1704, and a DPB (Decoded PictureBuffer) 1705.

The TB 1701 is a buffer that, when a TS packet including a video streamis output from the PID filter 1702, temporarily stores the TS packet asit is.

The MB 1702 is a buffer that, when a video stream is output from the TB1701 to the EB 1703, temporarily stores PES packets. When data istransferred from the TB 1701 to the MB 1702, the TS header of each TSpacket is removed.

The EB 1703 is a buffer that stores a picture in an encoded state(I-picture, B-picture and P-picture). When data is transferred from theMB 1702 to the EB 1703, the PES header is removed.

The compressed video decoder 1704 creates a frame/field image bydecoding each video access unit in a video elementary stream atrespective predetermined decode times (DTS). Possible compressionencoding formats of the video stream multiplexed on the AV clip includeMPEG2, MPEG4AVC, and VC1, and therefore the decoding scheme used by thecompressed video decoder 1704 can be changed in accordance with streamattributes. The compressed video decoder 1704 transfers each of thedecoded frame/field images to the DPB 1705, and writes each of thedecoded frame/field images in the primary video plane at respectivedisplay times (PTS).

The DPB 1705 is a buffer that temporarily stores the decoded frame/fieldimages. The compressed video decoder 1704 makes use of the DPB 1705 to,when decoding the video access units (e.g., a P-picture and a B-pictureencoded by the inter-picture predictive encoding), refer to picturesthat have already been decoded.

The secondary video decoder has the same structure as the primary videodecoder. The secondary video decoder performs decoding of an inputsecondary video stream, and writes resultant pictures to the secondaryvideo plane in accordance with respective display times (PTS).

The IG decoder extracts and decodes an interactive graphics stream fromthe TS packets input from source packetizers, and writes the resultantdecompressed graphics data to the IG plane in accordance with respectivedisplay times (PTS).

The PG decoder extracts and decodes a presentation graphics stream fromthe TS packets input from the source packetizers, and writes theresultant decompressed graphics data to the PG plane in accordance withrespective display times (PTS).

The primary audio decoder has a buffer. While accumulating data in thebuffer, the primary audio decoder extracts information such as a TSheader and a PES header, and performs audio stream decode processing toobtain decompressed LPCM-state audio data. The primary audio decoderoutputs the obtained audio data to the audio mixer in accordance withthe respective playback time (PTS). Possible compression encodingformats of the audio stream multiplexed on the AV clip include AC3 andDTS, and therefore the decoding scheme used to decode the compressedaudio is changed in accordance with stream attributes.

The secondary audio decoder has the same structure as the primary audiodecoder. The secondary audio decoder performs decoding of an inputsecondary audio stream, and outputs resultant decompressed LPCM-stateaudio data to the audio mixer in accordance with respective displaytimes. Possible compression encoding formats of the audio streammultiplexed on the AV clip include Dolby Digital Plus and DTS-HD LBR,and therefore the decoding scheme used to decode the compressed audio ischanged in accordance with stream attributes.

The audio mixer mixes (superimposes) the decompressed audio data outputfrom the primary audio decoder and the decompressed audio data outputfrom the secondary audio decoder with each other, and outputs theresultant audio to a speaker or the like.

The image processor decodes graphics data (PNG and JPEG) transferredfrom the program execution unit, and outputs the resultant decodedgraphics data to the image plane in accordance with a display timedesignated by the program execution unit.

This concludes the description of the structure of the 2D playbackdevice relating to the present invention.

(Principle of 3D Playback)

With reference to FIG. 80, the following describes the principle ofenabling stereoscopic viewing on a home-use screen. There are two majormethods to enable the stereoscopic viewing: a method that utilizesholography; and a method that utilizes parallax images.

The first method utilizing the holography is characterized in that itcan create 3D images of an object in such a manner that a human viewerrecognizes the three-dimensionality of the created 3D images in the sameway as he/she recognizes the three-dimensionality of the actual object.However, although a technical theory has already been established in thefield of holography, when it comes to playback of a video, it isextremely difficult to create holograms of a video with the currentholography technique, because doing so requires use of (i) a computerthat can perform an enormous amount of operations to create holograms ofthe video in real time, and (ii) a display device whose resolution ishigh enough to be able to draw thousands of linear materials in adistance of 1 mm. For this reason, there are almost no practicalexamples of holography that are commercially used.

The second method utilizing the parallax images is characterized inthat, after right-eye images and left-eye images are separatelyprepared, it enables stereoscopic viewing by making the right-eye imagesand the left-eye images only visible to the right eye and the left eye,respectively. FIG. 80 shows a user looking at a relatively small cubethat is on a straight line connecting the center of the user's face andthe center of the cube, as viewed from above. The top right viewexemplarily shows the cube as seen by the left eye of the user. Thebottom right view exemplarily shows the cube as seen by the right eye ofthe user.

The merit of the second method is that it can realize the stereoscopicviewing merely by preparing right-eye images and left-eye imagesseparately. As there are several technical ways to make the right-eyeand left-eye images only visible to the right eye and left-eye,respectively, the second method has already been practically implementedas different techniques.

One technique is called a “sequential segregation” method, with whichthe user views the left-eye and right-eye images, which are displayedalternately in the time axis direction on a screen, while wearingstereoscopic glasses (with liquid-crystal shutters). At this time, tothe user's eyes, a left-eye image and a corresponding right-eye imagelook superimposed over each other due to the afterimage effect.Accordingly, the user's eyes recognize that the pair of the left-eyeimage and the corresponding right-eye image is a 3D image. To be morespecific, while a left-eye image is being displayed on the screen, thestereoscopic glasses make the left-eye liquid-crystal shuttertransparent and the right-eye liquid-crystal shutter dark. Conversely,while a right-eye image is being displayed on the screen, thestereoscopic glasses make the right-eye liquid-crystal shuttertransparent and the left-eye liquid-crystal shutter dark. As statedearlier, this technique (alternate-frame sequencing) displays right-eyeand left-eye images alternately in the time axis direction. Thus, unlikean ordinary 2D movie that is displayed at 24 frames-per-second, thistechnique needs to display a total of 48 left-eye and right-eye imagesper second. Therefore, the alternate-frame sequencing is suitable foruse in a display device that can rewrite the screen at a relatively highspeed. The alternate-frame sequencing can also be used in any displaydevice that can rewrite the screen for a predetermined number of timesper second.

As opposed to the aforementioned sequential segregation method thatoutputs the left-eye and right-eye pictures alternately in the time axisdirection, there is another technique that simultaneously displays, on asingle screen, a left-eye picture and a right-eye picture horizontallynext to each other. Here, with the aid of a lenticular lens that issemicircular in shape and attached to the surface of the screen, pixelsconstituting the left-eye picture and pixels constituting the right-eyepicture are only presented to the left eye and the right eye,respectively. In the above manner, this technique can create theillusion of 3D images by presenting parallax pictures to the left eyeand the right eye. Note, the lenticular lens may be replaced withanother device (e.g., liquid crystal elements) that has the samefunction as the lenticular lens. Also, a vertical polarizing filter anda horizontal polarizing filter may be provided for left-eye pixels andright-eye pixels, respectively. Here, stereoscopic viewing can berealized by the viewer viewing the screen through polarizing glassescomposed of a vertical polarizing filter (for the left eye) and ahorizontal polarizing filter (for the right eye).

This stereoscopic viewing technique utilizing the parallax images hasbeen commonly used for attractions of amusement parks and the like, andhas already been established. Hence, this technique may be the closestform of technology that could be practically implemented for home use.It should be mentioned that many other methods/techniques have beensuggested to realize such stereoscopic viewing utilizing the parallaximages, such as a two-color separation method. Although thealternate-frame sequencing and the polarization glass technique areexplained in the present embodiment as examples of methods/techniques torealize the stereoscopic viewing, the stereoscopic viewing may berealized using other methods/techniques other than the aforementionedtwo techniques, as long as it is realized using parallax images.

In the present embodiment, a description is given of a method forrecording, on an information recording medium, parallax images used forstereoscopic viewing. Hereafter, an image for the left eye is referredto as a “left-eye image”, an image for the right eye is referred to as a“right-eye image”, and a pair of the left-eye image and thecorresponding right-eye image is referred to as a “3D image”. (Switchingbetween 2D and 3D displays)

Described below is the data structure of the BD-ROM, which is arecording medium pertaining to the present invention, for storing 3Dimages.

Basic parts of the data structure are the same as those of the datastructure for recording 2D video images. Therefore, the followingdescription focuses on extended or different parts of such datastructure. The following description will be given under the assumptionthat 3D images are recorded on a BD-ROM. Hereafter, a playback devicethat can only play back 2D images is referred to as a “2D playbackdevice”, and a playback device that can play back both of 2D images and3D images is referred to as a “2D/3D playback device”.

The following describes an index file (Index.bdmv) stored in a BD-ROMfor playing back stereoscopic images. FIG. 98 shows an example of anindex file (Index.bdmv) stored in a BD-ROM for playing back stereoscopicimages. In the example shown in FIG. 98, as a playlist, there areprepared a 2D PlayList 2601 showing a playback path of 2D images and a3D PlayList 2602 showing a playback path of 3D images. A title isselected by a user, and the executed BD program file checks if theplayback device is compliant with the 3D image playback according to aprogram stored therein. If the playback device is compliant with the 3Dimage playback, the executed BD program file checks if the user hasselected the playback of the 3D images, and switches a PlayList to beplayed back accordingly.

Also, a “3D existence flag” and a “2D/3D preference flag” are preparedfor the index file. The 3D existence flag is a flag that identifieswhether or not a PlayList for playing back the 3D images exists in thetitle. Since the 2D/3D playback device does not have to prepare for theplayback of the 3D images in a case where the flag shows “FALSE”, the2D/3D playback device can skip processing such as HDMI authentication,thereby performing processing at high speed. The 2D/3D preference flagis an identifier showing whether a content provider specifies theplayback of the 2D images or 3D images when the TV and the playbackdevice are capable of playing back both the 2D images and the 3D images.When the flag shows “3D”, the playback device can promptly performs theHDMI authentication since switching to a 2D mode is not necessary. Ingeneral, a large delay occurs during the HDMI authentication between theplayback device and the TV when the video stream attribute such as theframe rate is different. Therefore, when another switching is performedfrom the playback of the 2D images to the playback of the 3D imagesafter switching to the 2D images, a large delay occurs. Therefore, it ispossible to prevent a delay time of the HDMI authentication if theswitching to the playback of the 2D images can be skipped with use ofthe 2D/3D preference flag.

Note that the “3D existence flag” and the “2D/3D preference flag” may beset for each title instead of the index file as a whole.

FIG. 99 shows a selection flow of the 2D PlayList and the 3D PlayListaccording to the program in the BD program file.

In S2701, a value in PSR24 is checked. When the value is “0”, since theplayback device is a 2D playback device, the 2D PlayList is played back.When the value is “1”, the process advances to S2702.

In S2702, a menu screen is displayed to ask whether the user wishes forplayback of 2D images or 3D images. In accordance with a result of theuser's selection made with a remote control or the like, when the userwishes for the 2D image playback, the 2D PlayList is played back, andwhen the user wishes for the 3D image playback, the process advances toS2703.

In S2703, it is checked whether the display corresponds to the 3D imageplayback. For example, after the playback device is connected to thedisplay using HDMI, the playback device makes an inquiry to the displayas to whether the display corresponds to the 3D image playback. When thedisplay does not correspond to the 3D image playback, the display deviceplays back the 2D PlayList. Alternatively, the playback device maydisplay, on a menu screen or the like, a notification that informs theuser that the television is not ready for the playback. When the displaycorresponds to the 3D image playback, the display device plays back the3D PlayList.

Also, in the above is described that the parental level can be set inthe PSR13 in the 2D playback device. With this setting, control can beperformed such that only the user who is the appropriate age or over canplay back the BD-ROM disc. In addition to this parental level, a 3Dparental level in PSR30 is prepared for the 2D/3D playback device. Inthe 3D parental level is stored information on the age of the user whouses the 2D/3D playback device, as with the PSR13. The BD program fileof the title of the BD-Rom disc judges whether or not the playback ispermitted, with use of this PSR30 in addition to the PSR13. Since thePSR30 is the parental level regarding the playback of the 3D images, theparental level is controlled with use of the PSR13 in the 2D playbackdevice. With these two kinds of parental levels, control can beperformed, in view of physical effects on a small child in the processof growing, based on a demand that “small children cannot watch 3D imagebut 2D images”, for example. For example, a playlist to be played backmay be selected with reference to the PSR30 after it is checked that thedisplay supports the playback of the 3D image (S2703: YES) in the flowchart shown in FIG. 99.

Note that although the age information is stored in the PSR30 as withthe PSR13, in the PSR30 may be set whether the playback of the 3D imagesis prohibited or not.

Also, in the system parameter (in this example, the PSR31) is set theinformation showing “which of the 2D images and the 3D images the userprefers to be played back”. In the PSR31 is set, by the user via the OSDof the 2D/3D playback device, which of the playback of the 2D images andthe playback of the 3D images the user give a priority to. When thedisplay supports the playback of the 3D images, and information on thePSR31 shows that the user gives the priority to the playback of the 3Dimages, it is not necessary to switch to the playback of the 2D images.Therefore, the HDMI authentication can be promptly performed, and theplayback processing of the 3D images can be also promptly performed.Also, the BD program determines whether to playback 2D or 3D withreference to this PSR31, thereby enabling playback processing inaccordance with a user's preference.

Note that a BD program may refer to the PSR31 to determine a defaultselection button of a menu to be displayed by a BD program. For example,suppose that a menu prompts the user to branch to “2D video playback” or“3D video playback”. In this case, if the value of the PSR31 indicates“2D”, the user puts his cursor on a button of “2D video playback”. Ifthe value of the PSR31 indicates “3D”, the user puts his cursor on abutton of “3D video playback”.

The selection on “which of 2D playback and 3D playback user prefers”differs for each user who performs playback. In the case where the 2D/3Dplayback device includes a unit for identifying a person who is watchingthe 2D/3D playback device, the value of the PSR31 may be set dependingon a user who is currently watching the 2D/3D playback device. Forexample, suppose that three family members (father, mother, and child)use a 2D/3D playback device. The 2D/3D playback device manages anaccount for each user. In this case, by updating the value of the PSR31depending on a user who is currently logging in, it is possible toperform control in accordance with a preference of a person who isactually using the 2D/3D playback device.

The selection on “which of 2D playback and 3D playback user prefers” maybe performed by setting levels, instead of selecting between 2D and 3D.For example, four levels of “always 2D”, “rather 2D”, “rather 3D”, and“always 3D” may be set. With such a structure, it is possible to performplayback processing in a 2D/3D playback device much more in accordancewith a user's preference. For example, suppose that a PSR25 is used,which is a system parameter showing the status of a playback device. Inthis case, if the value of the PSR31 indicates the level “always 2D”,the value of the PSR25 is always set to the 2D mode. If the value of thePSR31 indicates the level “always 3D”, the value of the PSR25 is alwaysset to the 3D mode (L/R mode or DEPTH mode).

Next, the following describes the structure of a presentation graphicswith reference to FIG. 81. A subtitle entry displayed as shown in FIG.81 is composed of a plurality of subtitle data entries. Each of thesubtitle data entries is composed of composition information, windowinformation, palette information, and object information. Thecomposition information is information for defining the screen structureof subtitle data. The composition information stores therein croppinginformation of an object, a display position of the cropped object, awindow ID for identifying a window to be referred to, a palette ID foridentifying a palette to be referred to, and an object ID foridentifying the palette to be referred to. The window information storestherein a window region for defining a region in which the decoder willperform decoding together with a window ID. The object informationstores therein a graphics image together with the object ID. Thegraphics image is image data composed of 256 index colors, and iscompressed by a compression method such as the run-length compressionmethod. The palette information stores therein table information (CLUT)on a color to be used for the object together with the palette ID. Thetable is storable therein 256 colors, and each color is referable usinga corresponding color ID. The color ID has either value of 0-255. Thecolor ID having the value 255 fixedly corresponds to a clear andcolorless color.

FIG. 82 shows decoding processing of a presentation graphics. Firstly,in STEP 1, for each subtitle data entry, a compressed graphics imagespecified using a reference object ID of composition information isdecoded. In STEP 2, only necessary data is cropped from the graphicsimage using cropping information included in the compositioninformation. In STEP 3, in accordance with a display position includedin the composition information, a display position of the cropped dataon a graphic plane is determined. In STEP 4, object data correspondingto only a range of a window region included in the window informationspecified using a reference window ID included in the compositioninformation is rendered on the graphics plane. In STEP 5, a color isgiven to the graphic plane for display using palette informationspecified by a reference palette ID included in the compositioninformation. The display timing is in accordance with a PTS of a PESpacket in which the composition information is stored.

The following describes improvement in subtitle display.

When the “1 plane+offset” method is applied to a PG plane, in order tocreate subtitle data, it is necessary to adjust offset metadatadepending on the depth of a video image. This makes creation of subtitledata difficult.

In view of this problem, the following describes a method in whichregions of black frames on the screen that are not used for a mainfeature video of a movie work, the regions of the black frames arecollected on the upper side or the lower side on the screen, andsubtitle data is displayed on the regions of the black frames.

Since the black frames inserted in the video stream are unnecessaryregions, subtitle data may be displayed on the black frames. However, asshown in the right side on the upper level of FIG. 4A, the black frameprovided on each of the upper side and the lower side has only 131pixels. The black frame having this size is slightly small to insertsubtitle data. In view of this, as shown in FIGS. 4B and 4C, the mainfeature video is shifted upward or downward, and a black color is givento a region obtained after shifting the main feature video, and theblack frames provided on the upper side and the lower side are collectedin the upper side or the lower side. As a result, it is possible toprepare a black frame enough large to insert subtitle data.

The following describes the data structure for realizing this concept.

The basic parts of the data structure are the same as those for storing3D videos described in the above embodiments, and accordingly additionalparts or different parts from the above embodiments are mainly describedhere. Also, the following description of PG is applicable to IG or a subvideo in the same way as PG by replacing the PG with the IG or the subvideo.

FIG. 83 shows the structure of a playitem of 3D playlist. The streamadditional information 1311 of a PG stream included in a streamselection table includes a “shift value in video shift upward(PG_v_shift_value_for_Up)” and a “shift value in video shift downward(PG_v_shift_value_for_Down)”. The “shift value in video shift upward(PG_v_shift_value_for_UP)” represents a shift amount of the PG plane inthe case where the main video plane is shifted upward (the black framesare collected in the lower side), and the “shift value in video shiftdownward (PG_v_shift_value_for_Down)” represents a shift amount of thePG plane in the case where the main video plane is shifted downward (theblack frames are collected in the upper side). The 2D/3D playback deviceadjusts the shift amount of the PG plane based on the shift value. Themethod of plane overlaying is described later.

Next, the 2D/3D playback device relating to the preset embodiment isdescribed. FIG. 84 shows the structure of plane overlaying performed bythe 2D/3D playback device. Although the description is given here usinga PG plane as a representative example, the description is applicable toany plane such as a sub video plane, an IG plane, and an image plane.

In addition to the compositional elements described in the aboveembodiments, the 2D/3D playback device shown in FIG. 84 includes, avideo plane cropping unit 9701 that performs cropping processing of2D/left-eye video plane and right eye video plane, a PSR32 for writing ashift mode of a video, a PG plane cropping unit 9702 that performscropping processing of a PG plane, and a PSR33 in which a shift amountof a plane such as a PG plane.

The PSR32 shown in FIG. 25A is a system parameter of the 2D/3D playbackdevice, and indicates a shift mode of a video (video_shift_mode). Thevideo_shift_mode of the PSR32 includes three modes of “Keep, “Up, and“Down. A value 0 of the PSR32 indicates “Up”, and a value of 2 of thePSR32 indicates “Down”. The video plane cropping unit 9701 performscropping processing of a video plane in accordance with a video shiftmode written in the PSR32. The value of the PSR32 is set via an API of aBD program or a command.

In the case where the value of PSR32 indicates “Keep”, the video planecropping unit 9701 does not change the 2D/left-eye video plane and theright eye video plane, and proceeds to processing of superimposing withother plane, as shown in FIG. 25B(1). In the case where the value of thePSR32 indicates “Up”, the video plane cropping unit 9701 shifts upwardsthe 2D/left-eye video plane and the right eye video plane, respectively,crops a black frame from the upper region, and inserts the cropped blackframe into the lower region, as shown in FIG. 25B(2). Then, the videoplane cropping unit 9701 proceeds to processing of superimposing withthe plane. As a result, the black frame can be concentrated downward ofthe plane. Also, in the case where the value of the PSR32 indicates“Down”, the video plane cropping unit 9701 shifts downward the2D/left-eye video plane and the right eye video plane, respectively, andcrops a black frame from the lower region, and inserts the cropped blackframe into the upper region, as shown in FIG. 25B(3). Then, the videoplane cropping unit 9701 proceeds to processing of superimposing withthe plane. As a result, the black frame can be concentrated upward ofthe plane.

FIG. 37 shows a system parameter (PSR33 is used here) showing a shiftamount of each plane in the longitudinal axis direction. The shiftamount shown by the PSR33 includes a plane shift amount of video shiftupward and a plane shift amount of video shift downward. For example,the SPRM(33) of a PG plane includes “PG_shift_value_for_UP” and“PG_shift_value_for_Down”. The value of the PSR33 is updated with avalue (“PG_v_shift_value_for_Up” or “PG_v_shift_value_for_Down”) set inthe playlist due to switching between streams. Also, the SPRM(33) may beset via API of command of a BD program.

The PG plane cropping unit 9702 shown in FIG. 84 performs plane shiftdepending on a shift amount of the PG plane shown by the PSR33. Theshift processing and overlay processing of overlaying with a video planeperformed by the PG plane cropping unit 9702 are shown in FIG. 11 andFIG. 38. As shown in FIG. 11, the video_shift_mode of the PSR32indicates “Keep”, the PG plane cropping unit 9702 performs overlayprocessing of overlaying with the video plane without performing theshift processing. As shown in FIG. 38A, if the video_shift_mode of thePSR32 indicates “Up”, the PG plane cropping unit 9702 performs shiftprocessing of the PG plane using the value of the PG_shift_value_for_Upstored in the PSR33 to crop a part protruding from the plane andsuperimpose the cropped protruding part with the video plane. Byperforming such processing, it is possible to display a subtitle on alower side compared with a case of 2D playback, and display the subtitlein an appropriate position within a region of a black frame in the lowerside. As shown in FIG. 38B, the video_shift_mode of the PSR32 indicates“Down”, the PG plane cropping unit 9702 performs shift processing of thePG plane using the value of the PG_shift_value_for_Down stored in thePSR33 to crop a part protruding from the plane and superimpose thecropped protruding part with the video plane. By performing suchprocessing, it is possible to display a subtitle on an upper sidecompared with a case of 2D playback, and display the subtitle in anappropriate position within a region of a black frame in the upper side.

Note that in the structure shown in FIG. 84, offset processing in thehorizontal axis direction (1 plane+offset method) for preventing jumpingis omitted. Alternatively, it may be employed to add the mechanism ofcropping processing based on an offset value in the lateral axisdirection. With such a structure, even in the case where a subtitle isdisplayed on a region of a black frame, it is possible to make thesubtitle to look like jumping.

Note that in the case where a subtitle is displayed on a region of ablack frame as shown in FIG. 84, an offset value in the lateral axisdirection may be a fixed value. In such a case, it may be possible todefine a shift amount in the X-axis direction to additional informationshown in FIG. 83, store a value of the shift amount in a PSR in thesimilar way as in the PSR33, and perform offset processing in thelateral axis direction using the value. This enables easy data creation.

In the structure of the plane overlaying described with reference toFIG. 84, the shift amount in the Y-axis direction is stored in thePSR33. Alternatively, instead of setting a system parameter, it may bepossible to employ the structure in which the PG plane cropping unit9702 directly refers to the playlist.

In the case where the video_shift_mode indicates “Up” or “Down”, theshift amount of the video plane may be fixed to the size of each of theblack frames provided in the upper and lower sides of the plane (131pixels in the example shown in FIG. 4). Alternatively, an author or auser may set the shift amount without limitation. Further alternatively,it may be employed to prepare a new system parameter, store the shiftamount in the new system parameter, and set the shift amount via a BDprogram or a player OSD.

In the structure of the plane overlaying described with reference toFIG. 84, the description is given on processing of shifting the wholeplane using a value stored in the PSR33. Alternatively, the value may beused as a value to be added to a display position of the PG in thecomposition information. For example, in the case where the displayposition of the PG in the composition information is (x,y) and thevideo_shift_mode indicates “Keep”, the PG decoder displays acorresponding subtitle data entry in a position indicated by(x,y+PG_shift_value_for_UP). With such a structure, processing isreduced compared with plane shift. In such a use case,PG_shift_value_for_UP may be stored in the composition information.

As shown in FIG. 39, in the case where the video_shift_mode indicates“Up” or “Down”, plane shift results in a cropped region. Accordingly,there only needs to make a restriction such that no subtitle data is inthe cropped region. In other words, as shown in the right side of FIG.39, since a region other than a region surrounded by a dashed line has apossibility to be cropped, a display position of the PG is restrictedsuch that no subtitle data is displayed on the region other than theregion surrounded by the dashed line. The coordinate of the region isrepresented by (0,PG_v_shfit_value_for_Down),(0,height+PG_v_sfhit_value_for_Up), (width,PG_v_shfit_value_for_Down),and (width,height+PG_v_sfhit_value_for_Up). For example, ifPG_v_sfhit_value_for_Up indicates −a and PG_v_sfhit_value_for_Downindicates+b, the region is represented by (0,b), (0,height−a),(width,b), and (width,height−a). As the constraint conditions for PG,the display position is restricted so as not to go beyond the aboveregion, the display position to which the size of an object to bedisplayed is added is restricted so as not to go beyond the aboveregion, the display position of the window is restricted so as not to gobeyond the above region, and the display position of the window to whichthe window size is added is restricted so as not to go beyond the aboveregion, for example. Such constraint conditions can prevent display of apartially lacking.

Note that “video_shift_mode” may be added to the stream additionalinformation 1311 of the stream selection information, as shown in FIG.85. In this case, the structure of plane overlay processing performed inthe 2D/3D playback device is as shown in FIG. 86. The structure shown inFIG. 86 includes a PSR34 in addition. The PSR34 stores therein a flag ofOn/Off indicating whether to perform video shift. In other words, thePSR34 having the value 1 indicates to perform video shift. The PSR34having the value 0 indicates not to perform video shift. The PSR34 thatis a flag of On/Off indicating whether to perform video shift iscontrolled by a program execution unit or the like in accordance with amenu, for example. The PSR34 may be set in accordance with a useroperation such as OSD of a player. A video shift mode is stored in thePSR32. A value of the video shift mode is set based on additionalinformation of a subtitle stream selected by PG stream selection. If thePSR34 indicates On, the video plane cropping unit 9701 performs croppingprocessing of video plane based on video shift_mode_set in the PSR32. Ifthe PSR34 indicates Off, the video plane cropping unit 9701 does notperform the cropping processing. With such a structure, it is possibleto set an appropriate video_shift_mode for each subtitle.

As shown in FIG. 85, video_shift_mode is stored in the stream additionalinformation 1311 of the stream selection information such that PGstreams whose shift modes video_shift_mode has the same attribute areregistered in a row in the stream selection table. A remote control ofthe 2D/3D playback device generally includes a subtitle switchingbutton. A user operation is defined such that each time the user pressesthe subtitle switching button, PG streams sequentially switch in theorder of subtitle streams registered in the stream selection table. Inthe case where the user switches a subtitle using the subtitle switchingbutton of the remote control, the video plane frequently moves upwardand downward. As a result, the video becomes difficult to watch, and theuser has an uncomfortable feeling. Accordingly, PG streams whose shiftmodes video_shift_mode has the same attribute are registered in a row inthe stream selection table, as shown in FIG. 13. For example, in theexample shown in FIG. 13, subtitle entries 1-3 each have avideo_shift_mode=Keep, subtitle entries 4-5 each have a video_shiftmode=Up, and subtitle entries 6-9 each have a video_shift_mode=Down. Bycollectively arranging subtitles having the same video shift mode inthis way, it is possible to prevent frequent shift of the video plane.

In the case where the video_shift_mode instantly switches among “Keep”,“Up”, and “Down”, the user feels unnatural. Accordingly, thevideo_shift_mode preferably switches among “Keep”, “Up”, and “Down” witha smooth effect. In this case, shift processing of the PG plane ispreferably performed after completion of shift of the video plane.

In the present embodiment, the method has been described in which blackframes are dynamically collected in the upper region or the lower regionon the screen. Alternatively, the following structure may be employed,as shown in the upper level of FIG. 87. Specifically, a main featurevideo is arranged not in the middle of the screen but a slightly upperside of the screen so as to create a video stream, more black frames arearranged in the lower side so as to use the lower side for displayingsubtitles. With such a structure, the black frames do not need to bedynamically changed for displaying subtitles. As a result, the videos donot move upward and downward, and the user does not feel uncomfortable.

As described with reference to FIG. 81, in the palette information ofthe PG stream, a clear and colorless color is fixedly assigned to thecolor whose ID is 255. The 2D/3D playback device may control the valueof this color to create a black frame. Specifically, the value of thecolor whose ID is 255 is stored in a system parameter PSR37. The 2D/3Dplayback device changes the color whose ID is 255 of the PG plane inaccordance with the PSR37. With such a structure, by setting abackground color of a subtitle to the color whose ID is 255, thesubtitle is displayed using a transparent color and the background canbe seen through the subtitle in the normal state, as shown in the leftside on the lower level of FIG. 87. By changing the color whose ID is255 to an untransparent color, it is possible to change the backgroundcolor of the subtitle, as shown in the right side on the lower level ofFIG. 87. The value of PSR37 can be set on the menu screen of the BDprogram or the like.

Embodiment 9

The present embodiment describes an example structure of a playbackdevice (FIG. 100) for playing back the data of the structure describedin an earlier embodiment, which is realized by using an integratedcircuit 3.

A medium interface unit 1 receives (reads) data from the medium, andtransfers the data to the integrated circuit 3. Note that the mediuminterface unit 1 receives the data of the structure described in theearlier embodiment. The medium interface unit 1 is, for example: a discdrive when the medium is the optical disc or hard disk; a card interfacewhen the medium is the semiconductor memory such as the SD card or theUSB memory; a CAN tuner or Si tuner when the medium is broadcast wavesof broadcast including the CATV; or a network interface when the mediumis the Ethernet™, wireless LAN, or wireless public line.

A memory 2 is a memory for temporarily storing the data received (read)from the medium, and the data that is being processed by the integratedcircuit 3. For example, the SDRAM (Synchronous Dynamic Random AccessMemory), DDRx SDRAM (Double-Date-Ratex Synchronous Dynamic Random AccessMemory; x=1, 2, 3 . . . ) or the like is used as the memory 2. Note thatthe number of the memories 2 is not fixed, but may be one or two ormore, depending on the necessity.

The integrated circuit 3 is a system LSI for performing the video/audioprocessing onto the data transferred from the interface unit 1, andincludes a main control unit 6, a stream processing unit 5, a signalprocessing unit 7, an AV output unit 8, and a memory control unit 9.

The main control unit 6 includes a processor core having the timerfunction and the interrupt function. The processor core controls theintegrated circuit 3 as a whole according to the program stored in theprogram memory or the like. Note that the basic software such as the OS(operating software) is stored in the program memory or the like inadvance.

The stream processing unit 5, under the control of the main control unit6, receives the data transferred from the medium via the interface unit1 and stores it into the memory 2 via the data bus in the integratedcircuit 3. The stream processing unit 5, under the control of the maincontrol unit 6, also separates the received data into the video-basedata and the audio-base data. As described earlier, on the medium, AVclips for 2D/L including left-view video stream and AV clips for Rincluding right-view video stream are arranged in an interleaved manner,in the state where each clip is divided into some Extents. Accordingly,the main control unit 6 performs the control so that, when theintegrated circuit 3 receives the left-eye data including left-viewvideo stream, the received data is stored in the first region in thememory 2; and when the integrated circuit 3 receives the right-eye dataincluding right-view video stream, the received data is stored in thesecond region in the memory 2. Note that the left-eye data belongs tothe left-eye Extent, and the right-eye data belongs to the right-eyeExtent. Also note that the first and second regions in the memory 2 maybe regions generated by dividing a memory logically, or may bephysically different memories. Further note that although the presentembodiment presumes that the left-eye data including the left-view videostream is the main-view data, and the right-eye data including theright-view video stream is the sub-view data, the right-eye data may bethe main-view data and the left-eye data may be the sub-view data. Also,the graphics stream is multiplexed in either or both of the main-viewdata and the sub-view data.

The signal processing unit 7, under the control of the main control unit6, decodes, by an appropriate method, the video-base data and theaudio-base data separated by the stream processing unit 5. Thevideo-base data has been recorded after being encoded by a method suchas MPEG-2, MPEG-4 AVC, MPEG-4 MVC, or SMPTE VC-1. Also, the audio-basedata has been recorded after being compress-encoded by a method such asDolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or Linear PCM. Thus,the signal processing unit 7 decodes the video-base data and theaudio-base data by the methods corresponding thereto. Models of thesignal processing unit 7 are various decoders of Embodiment 1 shown inFIG. 16.

The memory control unit 9 mediates the access to the memory 2 from eachfunctional block in the integrated circuit 3.

The AV output unit 8, under the control of the main control unit 6,performs the superimposing of the video-base data having been decoded bythe signal processing unit 7, or format conversion of the video-basedata and the like, and outputs the data subjected to such processes tothe outside of the integrated circuit 3.

FIG. 101 is a functional block diagram showing a typical structure ofthe stream processing unit 5. The stream processing unit 5 includes adevice/stream interface unit 51, a demultiplexing unit 52, and aswitching unit 53.

The device/stream interface unit 51 is an interface for transferringdata between the interface unit 1 and the integrated circuit 3. Thedevice/stream interface unit 51 may be: SATA (Serial Advanced TechnologyAttachment), ATAPI (Advanced Technology Attachment Packet Interface), orPATA (Parallel Advanced Technology Attachment) when the medium is theoptical disc or the hard disk; a card interface when the medium is thesemiconductor memory such as the SD card or the USB memory; a tunerinterface when the medium is broadcast waves of broadcast including theCATV; or a network interface when the medium is the Ethernet, wirelessLAN, or wireless public line. The device/stream interface unit 51 mayhave a part of the function of the interface unit 1, or the interfaceunit 1 may be embedded in the integrated circuit 3, depending on thetype of the medium.

The demultiplexing unit 52 separates the playback data, transferred fromthe medium, including video and audio, into the video-base data and theaudio-base data. Each Extent, having been described earlier, is composedof source packets of video, audio, PG (subtitle), IG (menu) and the like(dependent source packets may not include audio). The demultiplexingunit 52 separates the playback data into video-base TS packets andaudio-base TS packets based on the PID (identifier) included in eachsource packet. The demultiplexing unit 52 transfers the data after theseparation to the signal processing unit 7. The data on which theprocessing has been performed is directly transferred to the signalprocessing unit 7, or is stored in the memory 2 and then transferred tothe signal processing unit 7. A model of the demultiplexing unit 52 is,for example, the source depacketizer and the PID filter of Embodiment 8as shown in FIG. 79. Also, a graphics stream, as a single stream, whichhas not been multiplexed with main view data or sub view data istransmitted to the signal processing unit 7 without being processed bythe demultiplexing unit 52.

The switching unit 53 switches the output destination (storagedestination) so that, when the device/stream interface unit 51 receivesthe left-eye data, the received data is stored in the first region inthe memory 2; and when the switching unit 53 receives the right-eyedata, the received data is stored in the second region in the memory 2.Here, the switching unit 53 is, for example, DMAC (Direct Memory AccessController). FIG. 102 is a conceptual diagram showing the switching unit53 and the peripheral when the switching unit 53 is DMAC. The DMAC,under the control of the main control unit 6, transmits the datareceived by the device stream interface and the data storage destinationaddress to the memory control unit 9. More specifically, the DMACswitches the output destination (storage destination) depending on thereceived data, by transmitting Address 1 (the first storage region) tothe memory control unit 9 when the device stream interface receives theleft-eye data, and transmitting Address 2 (the second storage region) tothe memory control unit 9 when the device stream interface receives theright-eye data. The memory control unit 9 stores data into the memory 2in accordance with the storage destination address sent from the DMAC.Note that a dedicated circuit for controlling the switching unit 53 maybe provided, instead of the main control unit 6.

In the above description, the device/stream interface unit 51,demultiplexing unit 52, and switching unit 53 are explained as a typicalstructure of the stream processing unit 5. However, the streamprocessing unit 5 may further include an encryption engine unit fordecrypting received encrypted data, key data or the like, a securemanagement unit for controlling the execution of a device authenticationprotocol between the medium and the playback device and for holding asecret key, and a controller for the direct memory access. In the above,it has been explained that, when the data received from the medium isstored into the memory 2, the switching unit 53 switches the storagedestination depending on whether the received data is left-eye data orright-eye data. However, not limited to this, the data received from themedium may be temporarily stored into the memory 2, and then, when thedata is to be transferred to the demultiplexing unit 52, the data may beseparated into the left-eye data and the right-eye data.

FIG. 103 is a functional block diagram showing a typical structure ofthe AV output unit 8. The AV output unit 8 includes an imagesuperimposing unit 81, a video output format converting unit 82, and anaudio/video output interface unit 83.

The image superimposing unit 81 superimposes the decoded video-basedata. More specifically, the image superimposing unit 81 superimposesthe PG (subtitle) and the IG (menu) onto the left-view video data or theright-view video data in units of pictures. A model of the imagesuperimposing unit 81 is, for example, Embodiment 1 and FIGS. 20-22.More specifically, decoded video data and subtitle data are stored in aregion of the memory 2 for storing data to be rendered in each plane.Here, the plane is a region included in the memory 2 or a virtual space.The image superimposing unit 81 superimposes a left-view plane with asubtitle plane corresponding thereto, and superimposes a right-viewplane with a subtitle plane corresponding thereto. Then, based on aregion-saving flag corresponding to subtitle data (stream) to besuperimposed, the left-view plane and the right-view plane are eachsuperimposed with the subtitle data such that the subtitle data issuperimposed in a display region for the subtitle data indicated by theregion-saving flag (for example, Embodiment 1 and FIG. 12). In otherwords, if the region-saving flag indicates the display region for thesubtitle data as the upper end, the left-view plane and the right-viewplane are each shifted downward in the vertical coordinate, andsuperimposed with subtitle data. If the region-saving flag indicates thedisplay region for the subtitle data as the lower end, the left-viewplane and the right-view plane are each shifted upward in the verticalcoordinate, and superimposed with subtitle data.

The video output format converting unit 82 performs the followingprocesses and the like as necessary: the resize process for enlarging orreducing the decoded video-base data; the IP conversion process forconverting the scanning method from the progressive method to theinterlace method and vice versa; the noise reduction process forremoving the noise; and the frame rate conversion process for convertingthe frame rate.

The audio/video output interface unit 83 encodes, in accordance with thedata transmission format, the video-base data, which has been subjectedto the image superimposing and the format conversion, and the decodedaudio-base data. Note that, as will be described later, the audio/videooutput interface unit 83 may be provided outside the integrated circuit3.

FIG. 104 is an example structure showing the AV output unit 8, or thedata output part of the playback device in more detail. The integratedcircuit 3 of the present embodiment and the playback device support aplurality of data transmission formats for the video-base data and theaudio-base data. The audio/video output interface unit 83 shown in FIG.103 corresponds to an analog video output interface unit 83 a, a digitalvideo/audio output interface unit 83 b, and an analog audio outputinterface unit 83 c.

The analog video output interface unit 83 a converts and encodes thevideo-base data, which has been subjected to the image superimposingprocess and the output format conversion process, into the analog videosignal format, and outputs the conversion result. The analog videooutput interface unit 83 a is, for example: a composite video encoderthat supports any of the NTSC method, PAL method, and SECAM method; anencoder for the S image signal (Y/C separation); an encoder for thecomponent image signal; or a DAC (D/A converter).

The digital video/audio output interface unit 83 b overlays the decodedaudio-base data with the video-base data having been subjected to theimage superimposing and the output format conversion, encrypts theoverlaid data, encodes in accordance with the data transmissionstandard, and outputs the encoded data. The digital video/audio outputinterface unit 83 b is, for example, HDMI (High-Definition MultimediaInterface).

The analog audio output interface unit 83 c, being an audio DAC or thelike, performs the D/A conversion onto the decoded audio-base data, andoutputs analog audio data.

The transmission format of the video-base data and audio-base data maybe switched depending on the data receiving device (data input terminal)supported by the display device/speaker 4, or may be switched inaccordance with the selection by the user. Furthermore, it is possibleto transmit a plurality of pieces of data corresponding to the samecontent in parallel by a plurality of transmission formats, not limitedto the transmission by a single transmission format.

In the above description, the image superimposing unit 81, video outputformat converting unit 82, and audio/video output interface unit 83 areexplained as a typical structure of the AV output unit 8. However, theAV output unit 8 may further include, for example, a graphics engineunit for performing the graphics processing such as the filter process,image overlaying, curvature drawing, and 3D display.

This completes the description of the structure of the playback devicein the present embodiment. Note that all of the functional blocksincluded in the integrated circuit 3 may not be embedded, and that,conversely, the memory 2 shown in FIG. 100 may be embedded in theintegrated circuit 3. Also, in the present embodiment, the main controlunit 6 and the signal processing unit 7 have been described as differentfunctional blocks. However, not limited to this, the main control unit 6may perform a part of the process performed by the signal processingunit 7.

Also, as shown in FIG. 107, the process performed by the playback devicein the present embodiment may be performed by the display device. Inthat case, the data received by the medium interface unit 1 is subjectedto the signal processing performed by the integrated circuit 3, and thevideo data after this processing is output via the display drive unit 10onto the display panel 11 and the audio data after this processing isoutput onto the speaker 12. Here, the AV output unit 8 has, for example,a structure shown in FIG. 108, and the data is transferred via the videooutput interface unit 84 and the audio output interface unit 85 that areprovided inside or outside the integrated circuit 3. Note that thedevice may be provided with a plurality of video output interface units84 and a plurality of audio output interface units 85, or may beprovided with an interface unit that is common to the video and theaudio.

The route of the control buses and the data buses in the integratedcircuit 3 is designed in an arbitrary manner depending on the processingprocedure of each processing block or the contents of the processing.However, the data buses may be arranged so that the processing blocksare connected directly as shown in FIG. 105, or maybe arranged so thatthe processing blocks are connected via the memory 2 (the memory controlunit 9) as shown in FIG. 106.

The integrated circuit 3 may be a multi-chip module that is generated byenclosing a plurality of chips into one package, and its outerappearance is one LSI.

It is also possible to realize the system LSI by using the FPGA (FieldProgrammable Gate Array) that can be re-programmed after themanufacturing of the LSI, or the reconfigurable processor in which theconnection and setting of the circuit cells inside the LSI can bereconfigured.

Next, the operation of the playback device having the above-describedstructure will be explained.

FIG. 109 is a flow chart showing a playback procedure in which data isreceived (read) from the medium, is decoded, and is output as a videosignal and an audio signal.

S1: data is received (read) from the medium (the medium interface unit 1and the stream processing unit 5).

S2: the data received (read) in S1 is separated into various data (thevideo-base data and the audio-base data) (the stream processing unit 5).

S3: the various data generated by the separation in S2 are decoded bythe appropriate format (the signal processing unit 7).

S4: among the various data decoded in S3, the video-base data issubjected to the superimposing process (the AV output unit 8).

S6: the video-base data and the audio-base data having been subjected tothe processes in S2 through S5 are output (the AV output unit 8).

FIG. 110 is a flow chart showing in more detail the playback procedure.Each of the operations and processes is performed under the control ofthe main control unit 6.

S101: the device/stream interface unit 51 of the stream processing unit5 receives (reads out) data (playlist, clip information, etc.) which isother than the data stored in the medium to be played back and isnecessary for playback of the data, via the interface unit 1, and storesthe received data into the memory 2 (the interface unit 1, thedevice/stream interface unit 51, the memory control unit 9, and thememory 2).

S102: the main control unit 6 recognizes the compression method of thevideo and audio data stored in the medium by referring to the streamattribute included in the received clip information, and initializes thesignal processing unit 7 so that the corresponding decode processing canbe performed (the main control unit 6).

S103: the device/stream interface unit 51 of the stream processing unit5 receives (reads out) the data of video/audio that is to be playedback, from the medium via the interface unit 1, and stores the receiveddata into the memory 2 via the stream processing unit 5 and the memorycontrol unit 9. Note that the data is received (read) in units ofExtents, and the main control unit 6 controls the switching unit 53 sothat, when the left-eye data is received (read), the received data isstored in the first region; and when the right-eye data is received(read), the received data is stored in the second region, and theswitching unit 53 switches the data output destination (storagedestination) (the interface unit 1, the device/stream interface unit 51,the main control unit 6, the switching unit 53, the memory control unit9, and the memory 2).

S104: the data stored in the memory 2 is transferred to thedemultiplexing unit 52 of the stream processing unit 5, and thedemultiplexing unit 52 identifies the video-base data (main video,sub-video), PG (subtitle), IG (menu), and audio-base data (audio,sub-audio) based on the PIDs included in the source packets constitutingthe stream data, and transfers the data to each corresponding decoder inthe signal processing unit 7 in units of TS packets (the demultiplexingunit 52).

S105: each decoder in the signal processing unit 7 performs the decodeprocess onto the transferred TS packets by the appropriate method (thesignal processing unit 7).

S106: among the video-base data decoded by the signal processing unit 7,the data corresponding to the left-view video stream and the right-viewvideo stream is resized based on the display device 4 (the video outputformat converting unit 82).

S107: the PG (subtitle) and IG (menu) are superimposed onto the videostream resized in S106 (the image superimposing unit 81).

S108: the IP conversion, which is a conversion of the scanning method,is performed onto the video data after the superimposing in 5107 (thevideo output format converting unit 82).

S109: the encoding, D/A conversion and the like are performed ontovideo-base data and the audio-base data having been subjected to theabove-described processes, based on the data output format of thedisplay device/speaker or the data transmission format for transmissionto the display device/speaker 4. For example, processing is performed onthe video-base data and the audio-base data so as to be outputted inanalog or digital format. The composite video signal, the S imagesignal, the component image signal and the like are supported for theanalog output of the video-base data. Also, HDMI is supported for thedigital output of the video-base data and the audio-base data. (theaudio/video output interface unit 83).

S110: the video-base data and the audio-base data having been subjectedto the process in S109 is output and transmitted to the displaydevice/speaker (the audio/video output interface unit 83, the displaydevice/speaker 4).

This completes the description of the operation procedure of theplayback device in the present embodiment. Note that the result ofprocess may be temporarily stored into the memory 2 each time a processis completed. Note that when the playback process is performed by thedisplay device shown in FIG. 107, the operation procedure is basicallythe same, and functional blocks corresponding to the functional blocksof the playback device shown in FIG. 100 perform the processessimilarly. Also, in the above operation procedure, the video outputformat converting unit 82 performs the resize process and the IPconversion process. However, not limited to this, the processes may beomitted as necessary, or other processes (noise reduction process, framerate conversion process, etc.) may be performed. Furthermore, theprocessing procedures may be changed if possible.

(Supplementary Notes)

Up to now, the present invention has been described through the bestembodiments that the Applicant recognize as of now. However, furtherimprovements or changes can be added regarding the following technicaltopics. Whether to select any of the embodiments or the improvements andchanges to implement the invention is optional and may be determined bythe subjectivity of the implementer.

(Offset Metadata)

Offset metadata described in the embodiments may be realized by not onlythe data formats described above but also other data formats. Thefollowing lists other data formats of offset metadata.

FIG. 89 shows a first data format of offset metadata.

In the first data format, offset metadata is stored in a clipinformation file. In this case, as shown in FIG. 89A, it may be possibleto include table information in which PTS and offset amounts of aplurality of pieces of offset_id are included. A specific syntax isshown in FIG. 89B.

FIG. 90 shows a second data format of offset metadata. Offset metadatadescribed in the embodiments is stored in a head access unit of eachGOP, and is applied to a frame included in the GOP. In the second dataformat, when offset metadata is stored in a clip information file,offset metadata is stored for each entry point, as shown in FIG. 90A. Aspecific syntax is structured so as to correspond to EP_ID that is an IDof an entry point, as shown in FIG. 90B. With such a structure, a PTS isidentifiable by the EP_ID. Accordingly, since a value of the PTS doesnot need to be stored compared with the data format shown in FIG. 89.This can reduce the data amount. Also, with such a structure, whenoffset metadata is stored in both of an access unit of a video streamand a clip information file, verification is easily performed forchecking whether the same offset metadata is stored in the access unitand the clip information file.

FIG. 91 shows a third data format of offset metadata. In theembodiments, an offset sequence is stored in offset metadata for eachoffset sequence ID, and an offset value is referenced using a referenceoffset sequence ID for each PG stream. In the third data format, suchoffset metadata is stored in a playlist information file. FIG. 91A showsa syntax of offset metadata to be stored in a playlist information file.A first loop 11201 is a loop for a playitem. number_of_offsets[playitem]represents the number of offset entries of the playitem.number_of_offset_id[playitem] represents the number of offset sequenceIDs. A second loop 11202 is a loop for offset entries of the playitem.Information included in one loop is defined as an offset entry.offset_frame_number represents the number of video frames starting withthe head in the playitem. The offset_frame_number may represent PTS.However, by setting the offset_frame_number to represent the number offrames, a data amount can be reduced. offset_frame_duration representsan interval in which an offset value between each two offset entries isinserted. number_of_suboffsets represents the number of offset values tobe inserted into an interval between offset_frame_number[i] and asubsequent offset entry. FIG. 91B shows a relationship among theoffset_frame_number[i], the offset_frame_duration[i], and thenumber_of_suboffsets[i]. An offset value is stored for each offset ID,as shown in the loop 11203. offset_frame_number may represent the numberof differential video frames showing difference from an immediatelyprevious offset entry.

FIG. 92 shows a fourth data format of offset metadata. The fourth dataformat is another data format for storing offset metadata in a playlistinformation file. As shown in FIG. 92A, a flag(is_same_as_previous_playitem) is additionally included which showswhether a current playitem is the same as a previous playitem. In orderto create a video image menu for BD-ROM loop, a structure is employed inwhich many playitems are repeated in a playlist as if there occurs aninfinite loop of a playitem that refers to the same clip as shown inFIG. 92B. In this case, if the same offset metadata equal in number toplayitems is prepared, a data amount excessively increases. As a result,it is necessary to increase a memory amount of the 2D/3D playbackdevice. Accordingly, when the is_same_as_previous_playitem indicates 1,the 2D/3D playback device refers to a piece of offset metadatainformation of an immediately previous playitem. As a result, it ispossible to reduce a data amount.

FIG. 93 shows a fifth data format of offset metadata.

The fifth data format is a yet another data format for storing offsetmetadata in a playlist information file. As shown in FIG. 93, areference ID (ref_playitem_id_of_same_offset_metadata) for a playitemusing the same offset metadata is additionally included. When“ref_playitem_id_of_same_offset_metadata” does not indicate 0xFFFFrepresenting invalid, the 2D/3D playback device applies the offsetmetadata that is the same as a playitem indicated by the“ref_playitem_id_of_same_offset_metadata”. With this structure, it isonly necessary to define one piece of offset metadata with respect to aplurality of playitems having the same offset metadata. This can reducethe data amount.

FIG. 94 shows a sixth data format of offset metadata.

The sixth data format is a yet another format for storing offsetmetadata in a playlist information file.

In this data format, a header in which loop is performed in units ofplayitems and a region in which offset metadata is stored are separatelyprovided, as shown in FIG. 94. A playitem is associated with a piece ofoffset metadata by offset_block_id. With this structure, in the casewhere a plurality of playitems using the same piece of offset metadataare included, it is only necessary to define one piece of offsetmetadata. This can reduce a data amount. Also, the header may storetherein an address value (start_address) of a file in which acorresponding piece of offset metadata is stored. This structurefacilitates access in units of playitems.

In the syntax shown in FIG. 89 to FIG. 94, an entry of offset metadatais composed of 7-bit “offset_direction,offset_value”. Alternatively,offset metadata may be prepared by using the difference from a certainsequence of offset metadata. This structure can decrease the size of“offset_direction,offset_value”.

As another data format, it may be possible to employ a structure inwhich offset metadata is embedded on an audio stream using audiowatermark technique. Alternatively, it may be possible to employ astructure in which offset metadata is embedded on a video stream usingvideo watermark technique.

(PG Stream)

In order to reduce the number of subtitles to suppress increase in theband of streams, it is effective to share one PG stream as one of a PGstream for use in the “1 plane+offset” method PG stream and either aleft-eye or right-eye PG stream for use in the 2 plane L/R method.

However, if such a structure is employed, there is a case where shiftoccurs between a position in which a depth between the left-eye graphicsand the right eye graphics is large (position in which the graphicsesprotrude toward the user) and a position in which the depth is small, asshown in FIG. 95. In such a case, each of the graphicses moves betweenright and left. In an example shown in FIG. 95, if subtitle data isshift from a scene having a small depth to a scene having a large depth,the left-eye graphics is shifted in the right direction, and the righteye graphics is shifted in the left direction. If the left-eye graphicsis used for the 2D display and the 1 plane+offset method, the left-eyegraphics is shifted in the left direction in the same way. This causesthe user to feel uncomfortable.

In view of this problem, in order to display the 2D display subtitle andthe 1 plane+offset method subtitle without causing the user to feeluncomfortable, the display position of the composition information isfixed, as shown in FIG. 96. Also, an offset (I_offset) for displaying asa 2 plane L/R method left-eye PG is separately prepared in thecomposition information. In the case where display is performed inaccordance with the 2 plane L/R method, the 2D/3D playback device addsthe offset value to the display position of the composition informationfor display. With such a structure, even in the case where the samestream is used for the 2D display subtitle, the 1 plane+offset methodsubtitle, and the 2 plane L/R method left-eye subtitle, it is possibleto perform display in any display mode without causing the user to feeluncomfortable.

(Speed Increase in Jump Playback)

FIG. 97A shows the structure in which extents in a FileBase and aFileDependent are interleaved with each other. In the figure, aninverted triangle attached to the head of a data region R[2] on the discindicates a position of an entry point of the FileDependent on the disc.An inverted triangle attached to the head of a data region L[2] on thedisc indicates a position of an entry point of the FileBase on the disc.Here, in the case where jump playback is performed from the entry point,the 2D/3D playback device loads data stored in R[2] that is a dataregion on the disc, and then starts decoding while reading L[2]. Untilcompletion of loading the data stored in R[2], the 2D/3D playback devicecannot read a subsequent L[2], and accordingly cannot start decoding.

In view of this, in order to reduce a time period from loading to theentry point to starting playback, the structure as shown in FIG. 97B isemployed. In FIG. 97B, a File2D indicates data regions L[0], L[1], L[2]for 2D, and L[3] on the disc. A FileSS indicates data regions L[0],L[1], L[2] for 3D, and L[3] on the disc. The L[2] for 2D and the L[2]for 3D are structured so as to have the same data. With such astructure, the same data can be read although different playback pathsare used. FIG. 97B shows the structure in which data of a right eye AVclip corresponding to the data region L[2] for 3D is interleaved insmall units (range indicated by an arrow 10701). With such a structure,in the case where the 2D/3D playback device starts playback from theentry point, it is possible to structure a head extent of theFileDependent smaller compared with the structure shown in FIG. 97A.This can reduce a time period from starting at the entry point to thestart of decoding.

(Additional Information)

Additional information may be incorporated into an extension informationfield of playlist information, as an extension stream selection tablethat includes information elements shown below.

An “upper end region flag” is a flag indicating whether there is anupper end region during playback of a PG_text subtitle stream.

An “upper end region stream entry” includes: a sub-path identifierreference (ref_to_Subpath_id) specifying a sub-path to which a playbackpath of a PG_text subtitle stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which the PG_textsubtitle stream is stored; and a packet identifier(ref_to_stream_PID_subclip) of the PG_text subtitle stream in thisstream file.

“Upper end region depth reference information” is reference informationfor referring an offset sequence for a PG_text subtitle stream in thecase where subtitles are displayed in the upper end region, andindicates an offset sequence for a PG_text subtitle stream in the casewhere subtitles are displayed in the upper end region. The playbackdevice should apply the offset, which is supplied by this field, to thePG plane.

A “lower end region flag” is a flag indicating whether there is a lowerend region during playback of a PG_text subtitle stream.

A “lower end region stream entry” includes: a sub-path identifierreference (ref_to_Subpath_id) specifying a sub-path to which a playbackpath of a PG_text subtitle stream belongs; a stream file reference(ref_to_subClip_entry_id) specifying a stream file in which the PG_textsubtitle stream is stored; and a packet identifier(ref_to_stream_PID_subclip) of the PG_text subtitle stream in thisstream file.

“Lower end region depth reference information” is reference informationfor referring an offset sequence for a PG_text subtitle stream in thecase where subtitles are displayed in the lower end region, andindicates an offset sequence for a PG_text subtitle stream in the casewhere subtitles are displayed in the lower end region. The playbackdevice should apply the offset, which is supplied by this field, to thePG plane.

(Playback of Optical Disc)

The BD-ROM drive is equipped with an optical head that includes asemiconductor laser, collimated lens, beam splitter, objective lens,collecting lens, and light detector. The light beams emitted from thesemiconductor laser pass through the collimated lens, beam splitter, andobjective lens, and are collected on the information surface of theoptical disc.

The collected light beams are reflected/diffracted on the optical disc,pass through the objective lens, beam splitter, and collimated lens, andare collected in the light detector. A playback signal is generateddepending on the amount of light collected in the light detector.

(Variations of Recording Medium)

The recording medium described in each Embodiment indicates a generalpackage medium as a whole, including the optical disc and thesemiconductor memory card. In each Embodiment, it is presumed, as oneexample, that the recording medium is an optical disc in which necessarydata is recorded in advance (for example, an existing read-only opticaldisc such as the BD-ROM or DVD-ROM). However, the present invention isnot limited to this. For example, the present invention may beimplemented as follows: (i) obtain a 3D content that includes the datanecessary for implementing the present invention and is distributed by abroadcast or via a network; (ii) record the 3D content into a writableoptical disc (for example, an existing writable optical disc such as theBD-RE, DVD-RAM) by using a terminal device having the function ofwriting into an optical disc (the function may be embedded in a playbackdevice, or the device may not necessarily be a playback device); and(iii) apply the optical disc recorded with the 3D content to theplayback device of the present invention.

Embodiments of Semiconductor Memory Card Recording Device and PlaybackDevice

The following describes embodiments of the recording device forrecording the data structure of each Embodiment into a semiconductormemory, and the playback device for playing back thereof.

First, the mechanism for protecting the copyright of the data recordedon the BD-ROM will be explained, as a presupposed technology.

Some of the data recorded on the BD-ROM may have been encrypted asnecessitated in view of the confidentiality of the data.

For example, the BD-ROM may contain, as encrypted data, the datacorresponding to a video stream, an audio stream, or a stream includingthese.

The following describes decryption of the encrypted data among the datarecorded on the BD-ROM.

The semiconductor memory card playback device stores in advance data(for example, a device key) that corresponds to a key that is necessaryfor decrypting the encrypted data recorded on the BD-ROM.

On the other hand, the BD-ROM is recorded in advance with (i) data (forexample, a medium key block (MKB) corresponding to the above-mentioneddevice key) that corresponds to a key that is necessary for decryptingthe encrypted data, and (ii) encrypted data (for example, an encryptedtitle key corresponding to the above-mentioned device key and MKB) thatis generated by encrypting the key itself that is necessary fordecrypting the encrypted data. Note here that the device key, MKB, andencrypted title key are treated as a set, and are further associatedwith an identifier (for example, a volume ID) written in an area (calledBCA) of the BD-ROM that cannot be copied in general. It is structuredsuch that encrypted data cannot be decrypted if these elements arecombined incorrectly. Only if the combination is correct, a key (forexample, a title key that is obtained by decrypting the encrypted titlekey by using the above-mentioned device key, MKB, and volume ID) that isnecessary for decrypting the encrypted data can be derived. Theencrypted data can be decrypted by using the derived key.

When a playback device attempts to play back a BD-ROM loaded in thedevice, it cannot play back the encrypted data unless the device itselfhas a device key that makes a pair (or corresponds to) the encryptedtitle key and MKB recorded on the BD-ROM. This is because the key (titlekey) that is necessary for decrypting the encrypted data has beenencrypted, and is recorded on the BD-ROM as the encrypted title key, andthe key that is necessary for decrypting the encrypted data cannot bederived if the combination of the MKB and the device key is not correct.

Conversely, when the combination of the encrypted title key, MKB, devicekey, and volume ID is correct, the video stream and audio stream aredecoded by the video decoder and the audio decoder with use of theabove-mentioned key (for example, a title key that is obtained bydecrypting the encrypted title key by using the device key, MKB, andvolume ID) that is necessary for decrypting the encrypted data. Theplayback device is structured in this way.

This completes the description of the mechanism for protecting thecopyright of the data recorded on the BD-ROM. It should be noted herethat this mechanism is not limited to the BD-ROM, but may be applicableto, for example, a readable/writable semiconductor memory (such as aportable semiconductor memory such as the SD card) for theimplementation.

Next, the playback procedure in the semiconductor memory card playbackdevice will be described. In the case in which the playback device playsback an optical disc, it is structured to read data via an optical discdrive, for example. On the other hand, in the case in which the playbackdevice plays back a semiconductor memory card, it is structured to readdata via an interface for reading the data from the semiconductor memorycard.

More specifically, the playback device may be structured such that, whena semiconductor memory card is inserted into a slot provided in theplayback device, the playback device and the semiconductor memory cardare electrically connected with each other via the semiconductor memorycard interface, and the playback device reads out data from thesemiconductor memory card via the semiconductor memory card interface.

Embodiments of Receiving Device

The playback device explained in each Embodiment may be realized as aterminal device that receives data (distribution data) that correspondsto the data explained in each Embodiment from a distribution server foran electronic distribution service, and records the received data into asemiconductor memory card.

Such a terminal device may be realized by structuring the playbackdevice explained in each Embodiment so as to perform such operations, ormay be realized as a dedicated terminal device that is different fromthe playback device explained in each Embodiment and stores thedistribution data into a semiconductor memory card. Here, a case wherethe playback device is used will be explained. Also, in thisexplanation, an SD card is used as the recording-destinationsemiconductor memory.

When the playback device is to record distribution data into an SDmemory card inserted in a slot provided therein, the playback devicefirst send requests a distribution server that stores distribution data,to transmit the distribution data. In so doing, the playback devicereads out identification information for uniquely identifying theinserted SD memory card (for example, identification informationuniquely assigned to each SD memory card, more specifically, the serialnumber or the like of the SD memory card), from the SD memory card, andtransmits the read identification information to the distribution servertogether with the distribution request.

The identification information for uniquely identifying the SD memorycard corresponds to, for example, the volume ID having been describedearlier.

On the other hand, the distribution server stores necessary data (forexample, video stream, audio stream and the like) in an encrypted statesuch that the necessary data can be decrypted by using a predeterminedkey (for example, a title key).

The distribution server, for example, holds a private key so that it candynamically generate different pieces of public key informationrespectively in correspondence with identification numbers uniquelyassigned to each semiconductor memory card.

Also, the distribution server is structured to be able to encrypt thekey (title key) itself that is necessary for decrypting the encrypteddata (that is to say, the distribution server is structured to be ableto generate an encrypted title key).

The generated public key information includes, for example, informationcorresponding to the above-described MKB, volume ID, and encrypted titlekey. With this structure, when, for example, a combination of theidentification number of the semiconductor memory card, the public keycontained in the public key information which will be explained later,and the device key that is recorded in the playback device in advance,is correct, a key (for example, a title key that is obtained bydecrypting the encrypted title key by using the device key, the MKB, andthe identification number of the semiconductor memory) necessary fordecrypting the encrypted data is obtained, and the encrypted data isdecrypted by using the obtained necessary key (title key).

Following this, the playback device records the received piece of publickey information and distribution data into a recording region of thesemiconductor memory card being inserted in the slot thereof.

Next, a description is given of an example of the method for decryptingand playing back the encrypted data among the data contained in thepublic key information and distribution data recorded in the recordingregion of the semiconductor memory card.

The received public key information stores, for example, a public key(for example, the above-described MKB and encrypted title key),signature information, identification number of the semiconductor memorycard, and device list being information regarding devices to beinvalidated.

The signature information includes, for example, a hash value of thepublic key information.

The device list is, for example, information for identifying the devicesthat might be played back in an unauthorized manner. The information,for example, is used to uniquely identify the devices, parts of thedevices, and functions (programs) that might be played back in anunauthorized manner, and is composed of, for example, the device key andthe identification number of the playback device that are recorded inthe playback device in advance, and the identification number of thedecoder provided in the playback device.

The following describes playing back the encrypted data among thedistribution data recorded in the recording region of the semiconductormemory card.

First, it is checked whether or not the decryption key itself can beused, before the encrypted data is decrypted by using the decryptionkey.

More specifically, the following checks are conducted. (1) A check onwhether the identification information of the semiconductor memory cardcontained in the public key information matches the identificationnumber of the semiconductor memory card stored in advance in thesemiconductor memory card. (2) A check on whether the hash value of thepublic key information calculated in the playback device matches thehash value included in the signature information. (3) A check, based onthe information included in the device list, on whether the playbackdevice to perform the playback is authentic (for example, the device keyshown in the device list included in the public key information matchesthe device key stored in advance in the playback device). These checksmay be performed in any order.

After the above described checks (1) through (3), the playback deviceperforms a control not to decrypt the encrypted data when any of thefollowing conditions is satisfied: (i) the identification information ofthe semiconductor memory card contained in the public key informationdoes not match the identification number of the semiconductor memorycard stored in advance in the semiconductor memory card; (ii) the hashvalue of the public key information calculated in the playback devicedoes not match the hash value included in the signature information; and(iii) the playback device to perform the playback is not authentic.

On the other hand, when all of the conditions: (i) the identificationinformation of the semiconductor memory card contained in the public keyinformation matches the identification number of the semiconductormemory card stored in advance in the semiconductor memory card; (ii) thehash value of the public key information calculated in the playbackdevice matches the hash value included in the signature information; and(iii) the playback device to perform the playback is authentic, aresatisfied, it is judged that the combination of the identificationnumber of the semiconductor memory, the public key contained in thepublic key information, and the device key that is recorded in theplayback device in advance, is correct, and the encrypted data isdecrypted by using the key necessary for the decryption (the title keythat is obtained by decrypting the encrypted title key by using thedevice key, the MKB, and the identification number of the semiconductormemory).

When the encrypted data is, for example, a video stream and an audiostream, the video decoder decrypts (decodes) the video stream by usingthe above-described key necessary for the decryption (the title key thatis obtained by decrypting the encrypted title key), and the audiodecoder decrypts (decodes) the audio stream by using the above-describedkey necessary for the decryption.

With such a structure, when devices, parts of the devices, and functions(programs) that might be used in an unauthorized manner are known at thetime of the electronic distribution, a device list showing such devicesand the like may be distributed. This enables the playback device havingreceived the list to inhibit the decryption with use of the public keyinformation (public key itself) when the playback device includesanything shown in the list. Therefore, even if the combination of theidentification number of the semiconductor memory, the public key itselfcontained in the public key information, and the device key that isrecorded in the playback device in advance, is correct, a control isperformed not to decrypt the encrypted data. This makes it possible toprevent the distribution data from being used by an unauthentic device.

It is preferable that the identifier of the semiconductor memory cardthat is recorded in advance in the semiconductor memory card is storedin a highly secure recording region. This is because, when theidentification number (for example, the serial number of the SD memorycard) that is recorded in advance in the semiconductor memory card istampered with, unauthorized copying becomes easy. More specifically,unique, although different identification numbers are respectivelyassigned to semiconductor memory cards, if the identification numbersare tampered with to be the same, the above-described judgment in (1)does not make sense, and as many semiconductor memory cards as tamperingmay be copied in an unauthorized manner.

For this reason, it is preferable that information such as theidentification number of the semiconductor memory card is stored in ahighly secure recording region.

To realize this, the semiconductor memory card, for example, may have astructure in which a recording region for recording highly confidentialdata such as the identifier of the semiconductor memory card(hereinafter, the recording region is referred to as a “second recordingregion”) is provided separately from a recording region for recordingregular data (hereinafter, the recording region is referred to as a“first recording region”), a control circuit for controlling accesses tothe second recording region is provided, and the second recording regionis accessible only through the control circuit.

For example, data may encrypted so that encrypted data is recorded inthe second recording region, and the control circuit may be embeddedwith a circuit for decrypting the encrypted data. In this structure,when an access is made to the second recording region, the controlcircuit decrypts the encrypted data and returns decrypted data. Asanother example, the control circuit may hold information indicating thelocation where the data is stored in the second recording region, andwhen an access is made to the second recording region, the controlcircuit identifies the corresponding storage location of the data, andreturns data that is read from the identified storage location.

An application, which is running on the playback device and is to recorddata onto the semiconductor memory card with use of the electronicdistribution, issues, to the control circuit via a memory cardinterface, an access request requesting to access the data (for example,the identification number of the semiconductor memory card) recorded inthe second recording region. Upon receiving the request, the controlcircuit reads out the data from the second recording region and returnsthe data to the application running on the playback device. It sends theidentification number of the semiconductor memory card and requests thedistribution server to distribute the data such as the public keyinformation, and corresponding distribution data. The public keyinformation and corresponding distribution data that are sent from thedistribution server are recorded into the first recording region.

Also, it is preferable that the application, which is running on theplayback device and is to record data onto the semiconductor memory cardwith use of the electronic distribution, checks in advance whether ornot the application is tampered with before it issues, to the controlcircuit via a memory card interface, an access request requesting toaccess the data (for example, the identification number of thesemiconductor memory card) recorded in the second recording region. Forchecking this, an existing digital certificate conforming to the X.509standard, for example, may be used.

Also, the distribution data recorded in the first recording region ofthe semiconductor memory card 1 may not necessarily be accessed via thecontrol circuit provided in the semiconductor memory card.

INDUSTRIAL APPLICABILITY

The information recording medium of the present invention stores a 3Dimage, but can be played back in both 2D-image playback devices and3D-image playback devices. This makes it possible to distribute moviecontents such as movie titles storing 3D images, without causing theconsumers to be conscious about the compatibility. This activates themovie market and commercial device market. Accordingly, the recordingmedium and the playback device of the present invention have highusability in the movie industry and commercial device industry.

REFERENCE SIGNS LIST

100: recording medium

200: playback device

300: display device

400: 3D glasses

The invention claimed is:
 1. A playback device for playing back a recording medium having a video stream, playlist information, and a subtitle stream, wherein the playlist information includes a stream selection table showing a stream entry and a stream attribute for the subtitle stream to be permitted to be played back in a monoscopic playback mode, the playback device comprises: a register operable to store information of a video shift mode of the playback device, the video shift mode including an upward shift mode and a downward shift mode, wherein when the playback device performs the upward shift mode based on the information stored in the register, the playback device shifts video data formed from the video stream in a video plane upward and locates subtitle data formed from the subtitle stream in a lower end of the video plane, and wherein when the playback device performs the downward shift mode based on the information stored in the register, the playback device shifts the video data formed from the video stream in the video plane downward and locates the subtitle data formed from the subtitle stream in an upper end of the video plane.
 2. A recording medium playback system comprising: a playback device; and a recording medium, wherein the recording medium has a video stream, playlist information, and a subtitle stream, wherein the playlist information includes a stream selection table showing a stream entry and a stream attribute for the subtitle stream to be permitted to be played back in a monoscopic playback mode, wherein the playback device has a register operable to store information of a video shift mode of the playback device, the video shift mode including an upward shift mode and a downward shift mode, wherein when the playback device performs the upward shift mode based on the information stored in the register, the playback device shifts video data formed from the video stream in a video plane upward and locates subtitle data formed from the subtitle stream in a lower end of the video plane, and wherein when the playback device performs the downward shift mode based on the information stored in the register, the playback device shifts the video data formed from the video stream in the video plane downward and locates the subtitle data formed from the subtitle stream in an upper end of the video plane. 